<PAGE> PAGE 1
000 A000000 10/31/99
000 C000000 0000918572
000 D000000 N
000 E000000 F
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0
000 J000000 A
001 A000000 STATE STREET RESEARCH SECURITIES TRUST
001 B000000 811-8322
001 C000000 6173571200
002 A000000 ONE FINANCIAL CENTER
002 B000000 BOSTON
002 C000000 MA
002 D010000 02111
002 D020000 2690
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
007 B000000 3
007 C010100 1
007 C010200 2
007 C020200 STATE STREET RESEARCH STRATEGIC INCOME FUND
007 C030200 N
007 C010300 3
007 C020300 STATE STREET RESEARCH GALILEO FUND
007 C030300 N
007 C010400 4
007 C020400 STATE STREET RESEARCH LEGACY FUND
007 C030400 N
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A00AA01 STATE STREET RESEARCH & MANAGEMENT COMPANY
008 B00AA01 A
008 C00AA01 801-18538
008 D01AA01 BOSTON
008 D02AA01 MA
008 D03AA01 02111
008 D04AA01 2690
011 A00AA01 STATE STREET RESEARCH INVESTMENT SERVICES INC
011 B00AA01 8-2646868
011 C01AA01 BOSTON
011 C02AA01 MA
011 C03AA01 02111
<PAGE> PAGE 2
011 C04AA01 2690
012 A00AA01 STATE STREET RESEARCH SERVICE CENTER
012 B00AA01 85-26468
012 C01AA01 BOSTON
012 C02AA01 MA
012 C03AA01 02111
012 C04AA01 2690
013 A00AA01 PRICEWATERHOUSECOOPERS LLP
013 B01AA01 BOSTON
013 B02AA01 MA
013 B03AA01 02110
014 A00AA01 STATE STREET RESEARCH INVESTMENT SERVICES INC
014 B00AA01 8-35442
014 A00AA02 METROPOLITAN LIFE INSURANCE COMPANY
014 B00AA02 8-14901
014 A00AA03 DELETE
014 A00AA04 DELETE
015 A00AA01 STATE STREET BANK & TRUST CO.
015 B00AA01 C
015 C01AA01 BOSTON
015 C02AA01 MA
015 C03AA01 02110
015 E01AA01 X
018 00AA00 Y
019 A00AA00 Y
019 B00AA00 23
019 C00AA00 STATESTRES
020 A000001 AUTRANET, INC.
020 B000001 13-2961507
020 C000001 49
020 A000002 FIRST GLOBAL SECURITIES, INC.
020 B000002 95-4307359
020 C000002 12
020 A000003 ABEL NOSER CORP
020 B000003 13-2833083
020 C000003 9
020 A000004 MONTGOMERY SECURITIES
020 C000004 9
020 A000005 LYNCH JONES AND RYAN INC
020 B000005 13-3356934
020 C000005 9
020 A000006 CHICAGO CORP
020 C000006 8
020 A000007 DONALDSON, LUFKIN & JENRETTE CORP.
020 B000007 13-2741729
020 C000007 6
020 A000008 STIFEL NICHOLAS & CO. INC
020 B000008 43-0538770
020 C000008 5
020 A000009 LEWCO SECS AGENT FOR WERTHEIM
020 B000009 13-2765944
<PAGE> PAGE 3
020 C000009 4
020 A000010 J.P. MORGAN SECURITIES, INC.
020 B000010 13-3224016
020 C000010 4
021 000000 189
022 A000001 GOLDMAN SACHS & CO.
022 B000001 13-5108880
022 C000001 1955
022 D000001 0
022 A000002 MORGAN STANLEY & CO. INC.
022 B000002 13-2655998
022 C000002 1929
022 D000002 0
022 A000003 HERZOG HEINE GEDULD, INC.
022 B000003 13-1955436
022 C000003 1029
022 D000003 0
022 A000004 CIBC WORLD MARKETS CORP
022 B000004 13-2798343
022 C000004 605
022 D000004 0
022 A000005 J.P. MORGAN SECURITIES, INC
022 B000005 13-3224016
022 C000005 538
022 D000005 0
022 A000006 RAYMOND JAMES & ASSOCIATES, INC.
022 C000006 0
022 D000006 470
022 A000007 KNIGHT SECURITIES L.P.
022 C000007 438
022 D000007 0
022 A000008 SALOMON SMITH BARNEY INC.
022 B000008 11-2418191
022 C000008 299
022 D000008 0
022 A000009 CHASE SECURITIES, INC.
022 B000009 13-3112953
022 C000009 232
022 D000009 0
022 A000010 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
022 B000010 13-5674085
022 C000010 194
022 D000010 0
023 C000000 7430
023 D000000 470
024 00AA00 Y
025 A00AA01 CHASE SECURITIES INC.
025 B00AA01 13-3112953
025 C00AA01 D
025 D00AA01 149
025 A00AA02 MORGAN STANLEY CAPITAL INC.
<PAGE> PAGE 4
025 B00AA02 13-2655998
025 C00AA02 D
025 D00AA02 75
025 A00AA03 CHASE SECURITIES INC.
025 B00AA03 13-3112953
025 C00AA03 E
025 D00AA03 437
025 D00AA04 0
025 D00AA05 0
025 D00AA06 0
025 D00AA07 0
025 D00AA08 0
026 A000000 Y
026 B000000 Y
026 C000000 Y
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 Y
049 00AA00 N
050 00AA00 N
051 00AA00 N
052 00AA00 N
053 A00AA00 Y
053 B00AA00 Y
053 C00AA00 N
054 A00AA00 Y
054 B00AA00 Y
054 C00AA00 N
054 D00AA00 N
054 E00AA00 N
054 F00AA00 N
054 G00AA00 Y
054 H00AA00 Y
054 I00AA00 N
054 J00AA00 Y
054 K00AA00 N
054 L00AA00 N
054 M00AA00 Y
054 N00AA00 N
054 O00AA00 N
055 A00AA00 N
055 B00AA00 N
056 00AA00 Y
057 00AA00 N
070 A01AA00 Y
070 A02AA00 Y
070 B01AA00 Y
<PAGE> PAGE 5
070 B02AA00 N
070 C01AA00 Y
070 C02AA00 N
070 D01AA00 Y
070 D02AA00 N
070 E01AA00 Y
070 E02AA00 Y
070 F01AA00 Y
070 F02AA00 N
070 G01AA00 Y
070 G02AA00 N
070 H01AA00 Y
070 H02AA00 N
070 I01AA00 N
070 I02AA00 N
070 J01AA00 Y
070 J02AA00 Y
070 K01AA00 Y
070 K02AA00 Y
070 L01AA00 Y
070 L02AA00 Y
070 M01AA00 Y
070 M02AA00 N
070 N01AA00 Y
070 N02AA00 Y
070 O01AA00 Y
070 O02AA00 N
070 P01AA00 N
070 P02AA00 N
070 Q01AA00 N
070 Q02AA00 N
070 R01AA00 N
070 R02AA00 N
077 A000000 N
077 Q010000 N
077 Q020000 N
077 Q030000 N
078 000000 N
080 A00AA00 FEDERAL INSURANCE CO.
080 C00AA00 25000
081 A00AA00 Y
081 B00AA00 35
082 A00AA00 N
082 B00AA00 0
083 A00AA00 N
083 B00AA00 0
084 A00AA00 N
084 B00AA00 0
085 A00AA00 Y
085 B00AA00 N
086 A010000 0
<PAGE> PAGE 6
086 A020000 0
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
086 F020000 0
031 A000100 0
031 B000100 0
032 000100 0
033 000100 0
037 000100 N
038 000100 0
039 000100 N
040 000100 Y
041 000100 N
042 A000100 0
042 B000100 0
042 C000100 0
042 D000100 0
042 E000100 0
042 F000100 0
042 G000100 0
042 H000100 0
043 000100 0
044 000100 0
048 000100 0.000
048 A010100 0
048 A020100 0.000
048 B010100 0
048 B020100 0.000
048 C010100 0
048 C020100 0.000
048 D010100 0
048 D020100 0.000
048 E010100 0
048 E020100 0.000
048 F010100 0
048 F020100 0.000
048 G010100 0
048 G020100 0.000
048 H010100 0
048 H020100 0.000
048 I010100 0
048 I020100 0.000
048 J010100 0
048 J020100 0.000
<PAGE> PAGE 7
048 K010100 0
048 K020100 0.000
066 A000100 N
067 000100 N
068 A000100 N
068 B000100 N
069 000100 N
072 I000100 0
072 J000100 0
072 K000100 0
072 L000100 0
072 M000100 0
072 N000100 0
072 O000100 0
072 P000100 0
072 Q000100 0
072 R000100 0
072 S000100 0
072 T000100 0
072 U000100 0
072 V000100 0
072 W000100 0
072 X000100 0
072 Y000100 0
072 Z000100 0
072AA000100 0
072BB000100 0
072CC010100 0
072CC020100 0
072DD010100 0
072DD020100 0
072EE000100 0
073 A010100 0.0000
073 A020100 0.0000
073 B000100 0.0000
073 C000100 0.0000
074 A000100 0
074 B000100 0
074 C000100 0
074 D000100 0
074 E000100 0
074 F000100 0
074 G000100 0
074 H000100 0
074 I000100 0
074 J000100 0
074 K000100 0
074 L000100 0
074 M000100 0
074 N000100 0
075 A000100 0
<PAGE> PAGE 8
075 B000100 0
076 000100 0.00
028 A010200 4071
028 A020200 296
028 A030200 0
028 A040200 3098
028 B010200 1906
028 B020200 306
028 B030200 0
028 B040200 1331
028 C010200 1873
028 C020200 305
028 C030200 0
028 C040200 5113
028 D010200 1428
028 D020200 290
028 D030200 0
028 D040200 3320
028 E010200 1242
028 E020200 0
028 E030200 0
028 E040200 2242
028 F010200 1189
028 F020200 1018
028 F030200 0
028 F040200 3645
028 G010200 11709
028 G020200 2215
028 G030200 0
028 G040200 18749
028 H000200 4130
029 000200 Y
030 A000200 119
030 B000200 4.50
030 C000200 0.00
031 A000200 14
031 B000200 0
032 000200 41
033 000200 64
034 000200 Y
035 000200 66
036 A000200 N
036 B000200 0
037 000200 N
038 000200 0
039 000200 N
040 000200 Y
041 000200 Y
042 A000200 2
042 B000200 0
042 C000200 0
<PAGE> PAGE 9
042 D000200 91
042 E000200 4
042 F000200 0
042 G000200 3
042 H000200 0
043 000200 351
044 000200 168
045 000200 Y
046 000200 N
047 000200 Y
048 000200 0.750
048 A010200 0
048 A020200 0.000
048 B010200 0
048 B020200 0.000
048 C010200 0
048 C020200 0.000
048 D010200 0
048 D020200 0.000
048 E010200 0
048 E020200 0.000
048 F010200 0
048 F020200 0.000
048 G010200 0
048 G020200 0.000
048 H010200 0
048 H020200 0.000
048 I010200 0
048 I020200 0.000
048 J010200 0
048 J020200 0.000
048 K010200 0
048 K020200 0.000
058 A000200 N
059 000200 Y
060 A000200 Y
060 B000200 Y
061 000200 2500
062 A000200 Y
062 B000200 0.0
062 C000200 0.0
062 D000200 0.3
062 E000200 0.0
062 F000200 0.0
062 G000200 0.0
062 H000200 0.0
062 I000200 5.0
062 J000200 0.0
062 K000200 0.0
062 L000200 0.0
062 M000200 7.3
<PAGE> PAGE 10
062 N000200 18.6
062 O000200 0.0
062 P000200 50.5
062 Q000200 16.1
062 R000200 2.2
063 A000200 0
063 B000200 7.5
064 A000200 N
064 B000200 N
066 A000200 N
067 000200 N
068 A000200 N
068 B000200 N
069 000200 N
071 A000200 88715
071 B000200 93850
071 C000200 101413
071 D000200 87
072 A000200 6
072 B000200 4510
072 C000200 82
072 D000200 0
072 E000200 0
072 F000200 400
072 G000200 0
072 H000200 0
072 I000200 82
072 J000200 70
072 K000200 0
072 L000200 19
072 M000200 9
072 N000200 56
072 O000200 0
072 P000200 0
072 Q000200 0
072 R000200 22
072 S000200 2
072 T000200 351
072 U000200 8
072 V000200 0
072 W000200 5
072 X000200 1024
072 Y000200 0
072 Z000200 3568
072AA000200 0
072BB000200 1804
072CC010200 0
072CC020200 5507
072DD010200 3642
072DD020200 0
072EE000200 0
<PAGE> PAGE 11
073 A010200 0.2500
073 A020200 0.2200
073 B000200 0.0000
073 C000200 0.0000
074 A000200 0
074 B000200 303
074 C000200 10239
074 D000200 92039
074 E000200 0
074 F000200 2155
074 G000200 0
074 H000200 0
074 I000200 6724
074 J000200 8930
074 K000200 0
074 L000200 2324
074 M000200 47
074 N000200 122761
074 O000200 15733
074 P000200 153
074 Q000200 0
074 R010200 0
074 R020200 0
074 R030200 0
074 R040200 7394
074 S000200 0
074 T000200 99481
074 U010200 15506
074 U020200 0
074 V010200 6.43
074 V020200 6.41
074 W000200 0.0000
074 X000200 4964
074 Y000200 0
075 A000200 0
075 B000200 106581
076 000200 0.00
028 A010300 5995
028 A020300 0
028 A030300 0
028 A040300 934
028 B010300 1193
028 B020300 150
028 B030300 0
028 B040300 791
028 C010300 1353
028 C020300 0
028 C030300 0
028 C040300 673
028 D010300 1189
028 D020300 0
<PAGE> PAGE 12
028 D030300 0
028 D040300 873
028 E010300 855
028 E020300 0
028 E030300 0
028 E040300 693
028 F010300 1281
028 F020300 0
028 F030300 0
028 F040300 811
028 G010300 11866
028 G020300 150
028 G030300 0
028 G040300 4775
028 H000300 7725
029 000300 Y
030 A000300 95
030 B000300 5.75
030 C000300 0.00
031 A000300 14
031 B000300 0
032 000300 2
033 000300 79
034 000300 Y
035 000300 38
036 A000300 N
036 B000300 0
037 000300 N
038 000300 0
039 000300 N
040 000300 Y
041 000300 Y
042 A000300 3
042 B000300 0
042 C000300 0
042 D000300 89
042 E000300 4
042 F000300 0
042 G000300 4
042 H000300 0
043 000300 152
044 000300 139
045 000300 Y
046 000300 N
047 000300 Y
048 000300 0.650
048 A010300 0
048 A020300 0.000
048 B010300 0
048 B020300 0.000
048 C010300 0
<PAGE> PAGE 13
048 C020300 0.000
048 D010300 0
048 D020300 0.000
048 E010300 0
048 E020300 0.000
048 F010300 0
048 F020300 0.000
048 G010300 0
048 G020300 0.000
048 H010300 0
048 H020300 0.000
048 I010300 0
048 I020300 0.000
048 J010300 0
048 J020300 0.000
048 K010300 0
048 K020300 0.000
058 A000300 N
059 000300 Y
060 A000300 Y
060 B000300 Y
061 000300 25000
062 A000300 N
062 B000300 0.0
062 C000300 0.0
062 D000300 0.0
062 E000300 0.0
062 F000300 0.0
062 G000300 0.0
062 H000300 0.0
062 I000300 0.0
062 J000300 0.0
062 K000300 0.0
062 L000300 0.0
062 M000300 0.0
062 N000300 0.0
062 O000300 0.0
062 P000300 0.0
062 Q000300 0.0
062 R000300 0.0
063 A000300 0
063 B000300 0.0
066 A000300 Y
066 B000300 N
066 C000300 N
066 D000300 Y
066 E000300 N
066 F000300 N
066 G000300 N
067 000300 N
068 A000300 N
<PAGE> PAGE 14
068 B000300 N
069 000300 N
071 A000300 34490
071 B000300 25899
071 C000300 50444
071 D000300 51
072 A000300 6
072 B000300 27
072 C000300 229
072 D000300 0
072 E000300 0
072 F000300 170
072 G000300 0
072 H000300 0
072 I000300 55
072 J000300 92
072 K000300 0
072 L000300 30
072 M000300 1
072 N000300 0
072 O000300 0
072 P000300 0
072 Q000300 0
072 R000300 12
072 S000300 3
072 T000300 152
072 U000300 9
072 V000300 0
072 W000300 0
072 X000300 524
072 Y000300 111
072 Z000300 -157
072AA000300 887
072BB000300 0
072CC010300 591
072CC020300 0
072DD010300 0
072DD020300 0
072EE000300 153
073 A010300 0.0000
073 A020300 0.0000
073 B000300 0.0300
073 C000300 0.0000
074 A000300 0
074 B000300 0
074 C000300 0
074 D000300 0
074 E000300 0
074 F000300 55081
074 G000300 0
074 H000300 0
<PAGE> PAGE 15
074 I000300 0
074 J000300 1345
074 K000300 98
074 L000300 70
074 M000300 138
074 N000300 56732
074 O000300 1213
074 P000300 54
074 Q000300 0
074 R010300 0
074 R020300 0
074 R030300 0
074 R040300 285
074 S000300 0
074 T000300 55180
074 U010300 4623
074 U020300 0
074 V010300 12.05
074 V020300 11.85
074 W000300 0.0000
074 X000300 7840
074 Y000300 0
075 A000300 0
075 B000300 52240
076 000300 0.00
028 A010400 25582
028 A020400 0
028 A030400 0
028 A040400 1325
028 B010400 20562
028 B020400 0
028 B030400 0
028 B040400 1597
028 C010400 24070
028 C020400 0
028 C030400 0
028 C040400 2434
028 D010400 24079
028 D020400 0
028 D030400 0
028 D040400 2718
028 E010400 22793
028 E020400 0
028 E030400 0
028 E040400 2879
028 F010400 23351
028 F020400 0
028 F030400 0
028 F040400 3363
028 G010400 140437
028 G020400 0
<PAGE> PAGE 16
028 G030400 0
028 G040400 14316
028 H000400 40753
029 000400 Y
030 A000400 851
030 B000400 5.75
030 C000400 0.00
031 A000400 92
031 B000400 0
032 000400 465
033 000400 294
034 000400 Y
035 000400 86
036 A000400 N
036 B000400 0
037 000400 N
038 000400 0
039 000400 N
040 000400 Y
041 000400 Y
042 A000400 1
042 B000400 0
042 C000400 0
042 D000400 88
042 E000400 5
042 F000400 0
042 G000400 6
042 H000400 0
043 000400 1017
044 000400 240
045 000400 Y
046 000400 N
047 000400 Y
048 000400 0.650
048 A010400 0
048 A020400 0.000
048 B010400 0
048 B020400 0.000
048 C010400 0
048 C020400 0.000
048 D010400 0
048 D020400 0.000
048 E010400 0
048 E020400 0.000
048 F010400 0
048 F020400 0.000
048 G010400 0
048 G020400 0.000
048 H010400 0
048 H020400 0.000
048 I010400 0
<PAGE> PAGE 17
048 I020400 0.000
048 J010400 0
048 J020400 0.000
048 K010400 0
048 K020400 0.000
058 A000400 N
059 000400 Y
060 A000400 Y
060 B000400 Y
061 000400 25000
062 A000400 N
062 B000400 0.0
062 C000400 0.0
062 D000400 0.0
062 E000400 0.0
062 F000400 0.0
062 G000400 0.0
062 H000400 0.0
062 I000400 0.0
062 J000400 0.0
062 K000400 0.0
062 L000400 0.0
062 M000400 0.0
062 N000400 0.0
062 O000400 0.0
062 P000400 0.0
062 Q000400 0.0
062 R000400 0.0
066 A000400 Y
066 B000400 N
066 C000400 N
066 D000400 Y
066 E000400 N
066 F000400 N
066 G000400 N
067 000400 N
068 A000400 N
068 B000400 N
069 000400 N
071 A000400 151443
071 B000400 28386
071 C000400 256114
071 D000400 11
072 A000400 6
072 B000400 236
072 C000400 1069
072 D000400 0
072 E000400 0
072 F000400 880
072 G000400 0
072 H000400 0
<PAGE> PAGE 18
072 I000400 30
072 J000400 56
072 K000400 0
072 L000400 28
072 M000400 6
072 N000400 134
072 O000400 0
072 P000400 0
072 Q000400 0
072 R000400 11
072 S000400 13
072 T000400 1017
072 U000400 9
072 V000400 0
072 W000400 2
072 X000400 2186
072 Y000400 0
072 Z000400 -881
072AA000400 0
072BB000400 6078
072CC010400 11440
072CC020400 0
072DD010400 0
072DD020400 0
072EE000400 0
073 A010400 0.0000
073 A020400 0.0000
073 B000400 0.0000
073 C000400 0.0000
074 A000400 1
074 B000400 0
074 C000400 10002
074 D000400 0
074 E000400 0
074 F000400 322491
074 G000400 0
074 H000400 0
074 I000400 0
074 J000400 2598
074 K000400 0
074 L000400 211
074 M000400 264
074 N000400 335567
074 O000400 0
074 P000400 373
074 Q000400 0
074 R010400 0
074 R020400 0
074 R030400 0
074 R040400 347
074 S000400 0
<PAGE> PAGE 19
074 T000400 334847
074 U010400 23102
074 U020400 0
074 V010400 14.70
074 V020400 14.43
074 W000400 0.0000
074 X000400 18400
074 Y000400 0
075 A000400 0
075 B000400 270744
076 000400 0.00
SIGNATURE DOUGLAS A. ROMICH
TITLE ASSISTANT TREASURER
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 041
<NAME> STATE STREET RESEARCH LEGACY FUND CLASS A
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 289,868,739
<INVESTMENTS-AT-VALUE> 332,492,651
<RECEIVABLES> 2,808,762
<ASSETS-OTHER> 265,447
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 335,566,824
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 720,108
<TOTAL-LIABILITIES> 720,108
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 298,654,599
<SHARES-COMMON-STOCK> 6,989,253
<SHARES-COMMON-PRIOR> 4,066,244
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 6,431,795
<ACCUM-APPREC-OR-DEPREC> 42,623,912
<NET-ASSETS> 334,846,716
<DIVIDEND-INCOME> 1,069,015
<INTEREST-INCOME> 236,075
<OTHER-INCOME> 0
<EXPENSES-NET> 2,186,089
<NET-INVESTMENT-INCOME> (880,999)
<REALIZED-GAINS-CURRENT> (6,078,212)
<APPREC-INCREASE-CURRENT> 11,440,468
<NET-CHANGE-FROM-OPS> 4,481,257
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3,306,172
<NUMBER-OF-SHARES-REDEEMED> (383,163)
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 130,602,222
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 353,583
<GROSS-ADVISORY-FEES> 879,918
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,193,031
<AVERAGE-NET-ASSETS> 270,744,000
<PER-SHARE-NAV-BEGIN> 14.42
<PER-SHARE-NII> (0.01)
<PER-SHARE-GAIN-APPREC> 0.22
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 14.63
<EXPENSE-RATIO> 1.12
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 042
<NAME> STATE STREET RESEARCH LEGACY FUND CLASS B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 289,868,739
<INVESTMENTS-AT-VALUE> 332,492,651
<RECEIVABLES> 2,808,762
<ASSETS-OTHER> 265,447
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 335,566,824
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 720,108
<TOTAL-LIABILITIES> 720,108
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 298,654,599
<SHARES-COMMON-STOCK> 6,729,266
<SHARES-COMMON-PRIOR> 6,188,684
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 6,431,795
<ACCUM-APPREC-OR-DEPREC> 42,623,912
<NET-ASSETS> 334,846,716
<DIVIDEND-INCOME> 1,069,015
<INTEREST-INCOME> 236,075
<OTHER-INCOME> 0
<EXPENSES-NET> 2,186,089
<NET-INVESTMENT-INCOME> (880,999)
<REALIZED-GAINS-CURRENT> (6,078,212)
<APPREC-INCREASE-CURRENT> 11,440,468
<NET-CHANGE-FROM-OPS> 4,481,257
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 936,071
<NUMBER-OF-SHARES-REDEEMED> (395,489)
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 130,602,222
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 353,583
<GROSS-ADVISORY-FEES> 879,918
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,193,031
<AVERAGE-NET-ASSETS> 270,744,000
<PER-SHARE-NAV-BEGIN> 14.28
<PER-SHARE-NII> (0.06)
<PER-SHARE-GAIN-APPREC> 0.21
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 14.43
<EXPENSE-RATIO> 1.87
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 043
<NAME> STATE STREET RESEARCH LEGACY FUND CLASS S
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 289,868,739
<INVESTMENTS-AT-VALUE> 332,492,651
<RECEIVABLES> 2,808,762
<ASSETS-OTHER> 265,447
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 335,566,824
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 720,108
<TOTAL-LIABILITIES> 720,108
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 298,654,599
<SHARES-COMMON-STOCK> 454,273
<SHARES-COMMON-PRIOR> 439,824
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 6,431,795
<ACCUM-APPREC-OR-DEPREC> 42,623,912
<NET-ASSETS> 334,846,716
<DIVIDEND-INCOME> 1,069,015
<INTEREST-INCOME> 236,075
<OTHER-INCOME> 0
<EXPENSES-NET> 2,186,089
<NET-INVESTMENT-INCOME> (880,999)
<REALIZED-GAINS-CURRENT> (6,078,212)
<APPREC-INCREASE-CURRENT> 11,440,468
<NET-CHANGE-FROM-OPS> 4,481,257
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 21,792
<NUMBER-OF-SHARES-REDEEMED> (7,343)
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 130,602,222
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 353,583
<GROSS-ADVISORY-FEES> 879,918
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,193,031
<AVERAGE-NET-ASSETS> 270,744,000
<PER-SHARE-NAV-BEGIN> 14.48
<PER-SHARE-NII> 0.01
<PER-SHARE-GAIN-APPREC> 0.21
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 14.70
<EXPENSE-RATIO> 0.87
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 044
<NAME> STATE STREET RESEARCH LEGACY FUND CLASS C
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 289,868,739
<INVESTMENTS-AT-VALUE> 332,492,651
<RECEIVABLES> 2,808,762
<ASSETS-OTHER> 265,447
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 335,566,824
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 720,108
<TOTAL-LIABILITIES> 720,108
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 298,654,599
<SHARES-COMMON-STOCK> 2,904,210
<SHARES-COMMON-PRIOR> 1,848,695
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 6,431,795
<ACCUM-APPREC-OR-DEPREC> 42,623,912
<NET-ASSETS> 334,846,716
<DIVIDEND-INCOME> 1,069,015
<INTEREST-INCOME> 236,075
<OTHER-INCOME> 0
<EXPENSES-NET> 2,186,089
<NET-INVESTMENT-INCOME> (880,999)
<REALIZED-GAINS-CURRENT> (6,078,212)
<APPREC-INCREASE-CURRENT> 11,440,468
<NET-CHANGE-FROM-OPS> 4,481,257
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1,183,540
<NUMBER-OF-SHARES-REDEEMED> (128,025)
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 130,602,222
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 353,583
<GROSS-ADVISORY-FEES> 879,918
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,193,031
<AVERAGE-NET-ASSETS> 270,744,000
<PER-SHARE-NAV-BEGIN> 14.28
<PER-SHARE-NII> (0.06)
<PER-SHARE-GAIN-APPREC> 0.21
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 14.43
<EXPENSE-RATIO> 1.87
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 045
<NAME> STATE STREET RESEARCH LEGACY FUND CLASS B1
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 289,868,739
<INVESTMENTS-AT-VALUE> 332,492,651
<RECEIVABLES> 2,808,762
<ASSETS-OTHER> 265,447
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 335,566,824
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 720,108
<TOTAL-LIABILITIES> 720,108
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 298,654,599
<SHARES-COMMON-STOCK> 6,025,394
<SHARES-COMMON-PRIOR> 1,712,635
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 6,431,795
<ACCUM-APPREC-OR-DEPREC> 42,623,912
<NET-ASSETS> 334,846,716
<DIVIDEND-INCOME> 1,069,015
<INTEREST-INCOME> 236,075
<OTHER-INCOME> 0
<EXPENSES-NET> 2,186,089
<NET-INVESTMENT-INCOME> (880,999)
<REALIZED-GAINS-CURRENT> (6,078,212)
<APPREC-INCREASE-CURRENT> 11,440,468
<NET-CHANGE-FROM-OPS> 4,481,257
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 4,403,021
<NUMBER-OF-SHARES-REDEEMED> (90,262)
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 130,602,222
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 353,583
<GROSS-ADVISORY-FEES> 879,918
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,193,031
<AVERAGE-NET-ASSETS> 270,744,000
<PER-SHARE-NAV-BEGIN> 14.28
<PER-SHARE-NII> (0.07)
<PER-SHARE-GAIN-APPREC> 0.22
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 14.43
<EXPENSE-RATIO> 1.87
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 031
<NAME> STATE STREET RESEARCH GALILEO FUND CLASS A
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 46,843,446
<INVESTMENTS-AT-VALUE> 55,081,239
<RECEIVABLES> 1,512,580
<ASSETS-OTHER> 138,260
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 56,732,079
<PAYABLE-FOR-SECURITIES> 1,213,108
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 339,460
<TOTAL-LIABILITIES> 1,552,568
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 46,225,661
<SHARES-COMMON-STOCK> 1,912,484
<SHARES-COMMON-PRIOR> 1,382,781
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 716,057
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 8,237,793
<NET-ASSETS> 55,179,511
<DIVIDEND-INCOME> 228,797
<INTEREST-INCOME> 27,105
<OTHER-INCOME> 0
<EXPENSES-NET> 413,049
<NET-INVESTMENT-INCOME> (157,147)
<REALIZED-GAINS-CURRENT> 886,981
<APPREC-INCREASE-CURRENT> 591,205
<NET-CHANGE-FROM-OPS> 1,321,039
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (62,973)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 720,444
<NUMBER-OF-SHARES-REDEEMED> (195,998)
<SHARES-REINVESTED> 5,257
<NET-CHANGE-IN-ASSETS> 8,407,617
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 18,305
<GROSS-ADVISORY-FEES> 169,781
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 527,511
<AVERAGE-NET-ASSETS> 52,240,308
<PER-SHARE-NAV-BEGIN> 11.73
<PER-SHARE-NII> (0.02)
<PER-SHARE-GAIN-APPREC> 0.32
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.03)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 12.00
<EXPENSE-RATIO> 1.26
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 032
<NAME> STATE STREET RESEARCH GALILEO FUND CLASS B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 46,843,446
<INVESTMENTS-AT-VALUE> 55,081,239
<RECEIVABLES> 1,512,580
<ASSETS-OTHER> 138,260
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 56,732,079
<PAYABLE-FOR-SECURITIES> 1,213,108
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 339,460
<TOTAL-LIABILITIES> 1,552,568
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 46,225,661
<SHARES-COMMON-STOCK> 1,609,745
<SHARES-COMMON-PRIOR> 1,660,009
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 716,057
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 8,237,793
<NET-ASSETS> 55,179,511
<DIVIDEND-INCOME> 228,797
<INTEREST-INCOME> 27,105
<OTHER-INCOME> 0
<EXPENSES-NET> 413,049
<NET-INVESTMENT-INCOME> (157,147)
<REALIZED-GAINS-CURRENT> 886,981
<APPREC-INCREASE-CURRENT> 591,205
<NET-CHANGE-FROM-OPS> 1,321,039
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (55,820)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 87,701
<NUMBER-OF-SHARES-REDEEMED> (142,576)
<SHARES-REINVESTED> 4,611
<NET-CHANGE-IN-ASSETS> 8,407,617
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 18,305
<GROSS-ADVISORY-FEES> 169,781
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 527,511
<AVERAGE-NET-ASSETS> 52,240,308
<PER-SHARE-NAV-BEGIN> 11.63
<PER-SHARE-NII> (0.06)
<PER-SHARE-GAIN-APPREC> 0.31
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.03)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 11.85
<EXPENSE-RATIO> 2.01
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 033
<NAME> STATE STREET RESEARCH GALILEO FUND CLASS S
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 46,843,446
<INVESTMENTS-AT-VALUE> 55,081,239
<RECEIVABLES> 1,512,580
<ASSETS-OTHER> 138,260
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 56,732,079
<PAYABLE-FOR-SECURITIES> 1,213,108
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 339,460
<TOTAL-LIABILITIES> 1,552,568
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 46,225,661
<SHARES-COMMON-STOCK> 493,111
<SHARES-COMMON-PRIOR> 493,619
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 716,057
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 8,237,793
<NET-ASSETS> 55,179,511
<DIVIDEND-INCOME> 228,797
<INTEREST-INCOME> 27,105
<OTHER-INCOME> 0
<EXPENSES-NET> 413,049
<NET-INVESTMENT-INCOME> (157,147)
<REALIZED-GAINS-CURRENT> 886,981
<APPREC-INCREASE-CURRENT> 591,205
<NET-CHANGE-FROM-OPS> 1,321,039
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (16,841)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 126
<NUMBER-OF-SHARES-REDEEMED> (2,040)
<SHARES-REINVESTED> 1,406
<NET-CHANGE-IN-ASSETS> 8,407,617
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 18,305
<GROSS-ADVISORY-FEES> 169,781
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 527,511
<AVERAGE-NET-ASSETS> 52,240,308
<PER-SHARE-NAV-BEGIN> 11.76
<PER-SHARE-NII> (0.00)
<PER-SHARE-GAIN-APPREC> 0.32
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.03)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 12.05
<EXPENSE-RATIO> 1.01
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 034
<NAME> STATE STREET RESEARCH GALILEO FUND CLASS C
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 46,843,446
<INVESTMENTS-AT-VALUE> 55,081,239
<RECEIVABLES> 1,512,580
<ASSETS-OTHER> 138,260
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 56,732,079
<PAYABLE-FOR-SECURITIES> 1,213,108
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 339,460
<TOTAL-LIABILITIES> 1,552,568
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 46,225,661
<SHARES-COMMON-STOCK> 281,597
<SHARES-COMMON-PRIOR> 315,259
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 716,057
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 8,237,793
<NET-ASSETS> 55,179,511
<DIVIDEND-INCOME> 228,797
<INTEREST-INCOME> 27,105
<OTHER-INCOME> 0
<EXPENSES-NET> 413,049
<NET-INVESTMENT-INCOME> (157,147)
<REALIZED-GAINS-CURRENT> 886,981
<APPREC-INCREASE-CURRENT> 591,205
<NET-CHANGE-FROM-OPS> 1,321,039
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (9,776)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 24,723
<NUMBER-OF-SHARES-REDEEMED> (59,156)
<SHARES-REINVESTED> 771
<NET-CHANGE-IN-ASSETS> 8,407,617
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 18,305
<GROSS-ADVISORY-FEES> 169,781
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 527,511
<AVERAGE-NET-ASSETS> 52,240,308
<PER-SHARE-NAV-BEGIN> 11.63
<PER-SHARE-NII> (0.06)
<PER-SHARE-GAIN-APPREC> 0.32
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.03)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 11.86
<EXPENSE-RATIO> 2.01
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 035
<NAME> STATE STREET RESEARCH GALILEO FUND CLASS B1
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 46,843,446
<INVESTMENTS-AT-VALUE> 55,081,239
<RECEIVABLES> 1,512,580
<ASSETS-OTHER> 138,260
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 56,732,079
<PAYABLE-FOR-SECURITIES> 1,213,108
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 339,460
<TOTAL-LIABILITIES> 1,552,568
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 46,225,661
<SHARES-COMMON-STOCK> 326,405
<SHARES-COMMON-PRIOR> 152,750
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 716,057
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 8,237,793
<NET-ASSETS> 55,179,511
<DIVIDEND-INCOME> 228,797
<INTEREST-INCOME> 27,105
<OTHER-INCOME> 0
<EXPENSES-NET> 413,049
<NET-INVESTMENT-INCOME> (157,147)
<REALIZED-GAINS-CURRENT> 886,981
<APPREC-INCREASE-CURRENT> 591,205
<NET-CHANGE-FROM-OPS> 1,321,039
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (7,209)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 187,865
<NUMBER-OF-SHARES-REDEEMED> (14,819)
<SHARES-REINVESTED> 609
<NET-CHANGE-IN-ASSETS> 8,407,617
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 18,305
<GROSS-ADVISORY-FEES> 169,781
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 527,511
<AVERAGE-NET-ASSETS> 52,240,308
<PER-SHARE-NAV-BEGIN> 11.63
<PER-SHARE-NII> (0.06)
<PER-SHARE-GAIN-APPREC> 0.31
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.03)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 11.85
<EXPENSE-RATIO> 2.01
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 021
<NAME> STATE STREET RESEARCH STRATEGIC INCOME FUND CLASS A
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 119,427,581
<INVESTMENTS-AT-VALUE> 111,459,608
<RECEIVABLES> 11,253,946
<ASSETS-OTHER> 47,600
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 122,761,154
<PAYABLE-FOR-SECURITIES> 15,732,575
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 7,547,757
<TOTAL-LIABILITIES> 23,280,332
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 111,129,019
<SHARES-COMMON-STOCK> 5,001,110
<SHARES-COMMON-PRIOR> 5,262,651
<ACCUMULATED-NII-CURRENT> 66,842
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 3,812,481
<ACCUM-APPREC-OR-DEPREC> (7,902,558)
<NET-ASSETS> 99,480,822
<DIVIDEND-INCOME> 82,477
<INTEREST-INCOME> 4,509,893
<OTHER-INCOME> 0
<EXPENSES-NET> 1,024,075
<NET-INVESTMENT-INCOME> 3,568,295
<REALIZED-GAINS-CURRENT> (1,804,483)
<APPREC-INCREASE-CURRENT> (5,507,108)
<NET-CHANGE-FROM-OPS> (3,743,296)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (1,232,947)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 713,713
<NUMBER-OF-SHARES-REDEEMED> (1,080,866)
<SHARES-REINVESTED> 105,612
<NET-CHANGE-IN-ASSETS> (12,210,043)
<ACCUMULATED-NII-PRIOR> 140,066
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 2,007,998
<GROSS-ADVISORY-FEES> 399,679
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1,026,684
<AVERAGE-NET-ASSETS> 106,581,067
<PER-SHARE-NAV-BEGIN> 6.88
<PER-SHARE-NII> 0.23
<PER-SHARE-GAIN-APPREC> (0.44)
<PER-SHARE-DIVIDEND> (0.24)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 6.43
<EXPENSE-RATIO> 1.54
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 022
<NAME> STATE STREET RESEARCH STRATEGIC INCOME FUND CLASS B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 119,427,581
<INVESTMENTS-AT-VALUE> 111,459,608
<RECEIVABLES> 11,253,946
<ASSETS-OTHER> 47,600
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 122,761,154
<PAYABLE-FOR-SECURITIES> 15,732,575
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 7,547,757
<TOTAL-LIABILITIES> 23,280,332
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 111,129,019
<SHARES-COMMON-STOCK> 5,809,701
<SHARES-COMMON-PRIOR> 6,423,079
<ACCUMULATED-NII-CURRENT> 66,842
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 3,812,481
<ACCUM-APPREC-OR-DEPREC> (7,902,558)
<NET-ASSETS> 99,480,822
<DIVIDEND-INCOME> 82,477
<INTEREST-INCOME> 4,509,893
<OTHER-INCOME> 0
<EXPENSES-NET> 1,024,075
<NET-INVESTMENT-INCOME> 3,568,295
<REALIZED-GAINS-CURRENT> (1,804,483)
<APPREC-INCREASE-CURRENT> (5,507,108)
<NET-CHANGE-FROM-OPS> (3,743,296)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (1,317,385)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 170,958
<NUMBER-OF-SHARES-REDEEMED> (919,901)
<SHARES-REINVESTED> 134,901
<NET-CHANGE-IN-ASSETS> (12,210,043)
<ACCUMULATED-NII-PRIOR> 140,066
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 2,007,998
<GROSS-ADVISORY-FEES> 399,679
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1,026,684
<AVERAGE-NET-ASSETS> 106,581,067
<PER-SHARE-NAV-BEGIN> 6.87
<PER-SHARE-NII> 0.21
<PER-SHARE-GAIN-APPREC> (0.45)
<PER-SHARE-DIVIDEND> (0.22)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 6.41
<EXPENSE-RATIO> 2.29
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 023
<NAME> STATE STREET RESEARCH STRATEGIC INCOME FUND CLASS S
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 119,427,581
<INVESTMENTS-AT-VALUE> 111,459,608
<RECEIVABLES> 11,253,946
<ASSETS-OTHER> 47,600
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 122,761,154
<PAYABLE-FOR-SECURITIES> 15,732,575
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 7,547,757
<TOTAL-LIABILITIES> 23,280,332
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 111,129,019
<SHARES-COMMON-STOCK> 1,527,694
<SHARES-COMMON-PRIOR> 1,696,253
<ACCUMULATED-NII-CURRENT> 66,842
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 3,812,481
<ACCUM-APPREC-OR-DEPREC> (7,902,558)
<NET-ASSETS> 99,480,822
<DIVIDEND-INCOME> 82,477
<INTEREST-INCOME> 4,509,893
<OTHER-INCOME> 0
<EXPENSES-NET> 1,024,075
<NET-INVESTMENT-INCOME> 3,568,295
<REALIZED-GAINS-CURRENT> (1,804,483)
<APPREC-INCREASE-CURRENT> (5,507,108)
<NET-CHANGE-FROM-OPS> (3,743,296)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (401,686)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 11,037
<NUMBER-OF-SHARES-REDEEMED> (204,178)
<SHARES-REINVESTED> 24,582
<NET-CHANGE-IN-ASSETS> (12,210,043)
<ACCUMULATED-NII-PRIOR> 140,066
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 2,007,998
<GROSS-ADVISORY-FEES> 399,679
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1,026,684
<AVERAGE-NET-ASSETS> 106,581,067
<PER-SHARE-NAV-BEGIN> 6.89
<PER-SHARE-NII> 0.24
<PER-SHARE-GAIN-APPREC> (0.46)
<PER-SHARE-DIVIDEND> (0.25)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 6.42
<EXPENSE-RATIO> 1.29
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 024
<NAME> STATE STREET RESEARCH STRATEGIC INCOME FUND CLASS C
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 119,427,581
<INVESTMENTS-AT-VALUE> 111,459,608
<RECEIVABLES> 11,253,946
<ASSETS-OTHER> 47,600
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 122,761,154
<PAYABLE-FOR-SECURITIES> 15,732,575
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 7,547,757
<TOTAL-LIABILITIES> 23,280,332
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 111,129,019
<SHARES-COMMON-STOCK> 2,137,388
<SHARES-COMMON-PRIOR> 2,322,361
<ACCUMULATED-NII-CURRENT> 66,842
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 3,812,481
<ACCUM-APPREC-OR-DEPREC> (7,902,558)
<NET-ASSETS> 99,480,822
<DIVIDEND-INCOME> 82,477
<INTEREST-INCOME> 4,509,893
<OTHER-INCOME> 0
<EXPENSES-NET> 1,024,075
<NET-INVESTMENT-INCOME> 3,568,295
<REALIZED-GAINS-CURRENT> (1,804,483)
<APPREC-INCREASE-CURRENT> (5,507,108)
<NET-CHANGE-FROM-OPS> (3,743,296)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (513,984)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 332,101
<NUMBER-OF-SHARES-REDEEMED> (572,144)
<SHARES-REINVESTED> 55,070
<NET-CHANGE-IN-ASSETS> (12,210,043)
<ACCUMULATED-NII-PRIOR> 140,066
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 2,007,998
<GROSS-ADVISORY-FEES> 399,679
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1,026,684
<AVERAGE-NET-ASSETS> 106,581,067
<PER-SHARE-NAV-BEGIN> 6.87
<PER-SHARE-NII> 0.21
<PER-SHARE-GAIN-APPREC> (0.45)
<PER-SHARE-DIVIDEND> (0.22)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 6.41
<EXPENSE-RATIO> 2.29
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000918572
<NAME> STATE STREET RESEARCH SECURITIES TRUST
<SERIES>
<NUMBER> 025
<NAME> STATE STREET RESEARCH STRATEGIC INCOME FUND CLASS B1
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> APR-30-2000
<PERIOD-END> OCT-31-1999
<INVESTMENTS-AT-COST> 119,427,581
<INVESTMENTS-AT-VALUE> 111,459,608
<RECEIVABLES> 11,253,946
<ASSETS-OTHER> 47,600
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 122,761,154
<PAYABLE-FOR-SECURITIES> 15,732,575
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 7,547,757
<TOTAL-LIABILITIES> 23,280,332
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 111,129,019
<SHARES-COMMON-STOCK> 1,030,073
<SHARES-COMMON-PRIOR> 542,562
<ACCUMULATED-NII-CURRENT> 66,842
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 3,812,481
<ACCUM-APPREC-OR-DEPREC> (7,902,558)
<NET-ASSETS> 99,480,822
<DIVIDEND-INCOME> 82,477
<INTEREST-INCOME> 4,509,893
<OTHER-INCOME> 0
<EXPENSES-NET> 1,024,075
<NET-INVESTMENT-INCOME> 3,568,295
<REALIZED-GAINS-CURRENT> (1,804,483)
<APPREC-INCREASE-CURRENT> (5,507,108)
<NET-CHANGE-FROM-OPS> (3,743,296)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (175,517)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 534,514
<NUMBER-OF-SHARES-REDEEMED> (65,246)
<SHARES-REINVESTED> 18,243
<NET-CHANGE-IN-ASSETS> (12,210,043)
<ACCUMULATED-NII-PRIOR> 140,066
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 2,007,998
<GROSS-ADVISORY-FEES> 399,679
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1,026,684
<AVERAGE-NET-ASSETS> 106,581,067
<PER-SHARE-NAV-BEGIN> 6.87
<PER-SHARE-NII> 0.21
<PER-SHARE-GAIN-APPREC> (0.45)
<PER-SHARE-DIVIDEND> (0.22)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 6.41
<EXPENSE-RATIO> 2.29
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
