<PAGE> PAGE 1
000 A000000 08/31/1999
000 C000000 0001063265
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 MSDW S&P 500 SELECT FUND
001 B000000 811-8809
001 C000000 2123921600
002 A000000 2 WORLD TRADE CENTER
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10048
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A000001 MORGAN STANLEY DEAN WITTER ADVISORS INC.
008 B000001 A
008 C000001 801-42061
008 D010001 NEW YORK
008 D020001 NY
008 D030001 10048
011 A000001 MORGAN STANLEY DEAN WITTER DISTRIBUTORS INC.
011 B000001 8-45262
011 C010001 NEW YORK
011 C020001 NY
011 C030001 10048
012 A000001 MORGAN STANLEY DEAN WITTER TRUST FSB
012 B000001 84-1785
012 C010001 JERSEY CITY
012 C020001 NJ
012 C030001 07311
013 A000001 PRICEWATERHOUSECOOPERS LLP
013 B010001 NEW YORK
013 B020001 NY
<PAGE> PAGE 2
013 B030001 10036
014 A000001 DEAN WITTER REYNOLDS INC.
014 B000001 8-14172
014 A000002 MORGAN STANLEY & CO. INCORPORATED
014 B000002 8-15869
015 A000001 BANK OF NEW YORK (THE)
015 B000001 C
015 C010001 NEW YORK
015 C020001 NY
015 C030001 10286
015 E010001 X
018 000000 Y
019 A000000 Y
019 B000000 127
019 C000000 MSDW-FUNDS
020 A000001 CS FIRST BOSTON CORP.
020 B000001 13-5659485
020 C000001 21
020 A000002 SALOMON SMITH BARNEY INC.
020 B000002 13-1912900
020 C000002 3
020 A000003 ABN AMRO CHICAGO CORP.
020 B000003 13-3227945
020 C000003 0
020 A000004 PRUDENTIAL SECURITIES INC.
020 B000004 22-2347336
020 C000004 0
020 A000005 INSTINET CORP.
020 B000005 13-3443395
020 C000005 0
020 A000006 CANTOR FITZGERALD
020 B000006 95-1786286
020 C000006 0
020 A000007 DEUTSCHE BANK SECURITIES CORP.
020 B000007 13-2730828
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 24
022 A000001 BANK OF NEW YORK (THE)
022 B000001 13-5160382
022 C000001 309239
022 D000001 0
022 A000002 GOLDMAN SACHS & CO.
022 B000002 13-5108880
022 C000002 217458
022 D000002 0
022 A000003 BANC OF AMERICA SECURITIES LLC
022 B000003 56-2058405
022 C000003 80686
<PAGE> PAGE 3
022 D000003 0
022 A000004 BANK OF AMERICA NT & SA
022 B000004 94-1687665
022 C000004 65537
022 D000004 0
022 A000005 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
022 B000005 13-5674085
022 C000005 45066
022 D000005 0
022 A000006 CS FIRST BOSTON CORP.
022 B000006 13-5659485
022 C000006 2627
022 D000006 160
022 A000007 SALOMON SMITH BARNEY INC.
022 B000007 13-1912900
022 C000007 996
022 D000007 9
022 A000008 PRUDENTIAL SECURITIES INC.
022 B000008 22-2347336
022 C000008 113
022 D000008 0
022 C000009 0
022 D000009 0
022 C000010 0
022 D000010 0
023 C000000 721720
023 D000000 168652
024 000000 Y
025 A000001 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
025 B000001 13-5674085
025 C000001 E
025 D000001 300
025 A000002 BANK OF AMERICA NT & SA
025 B000002 94-1687665
025 C000002 E
025 D000002 1526
025 A000003 BANK OF NEW YORK (THE)
025 B000003 13-5160382
025 C000003 E
025 D000003 327
025 A000004 BANK OF NEW YORK (THE)
025 B000004 13-5160382
025 C000004 D
025 D000004 3903
025 D000005 0
025 D000006 0
025 D000007 0
025 D000008 0
026 A000000 N
026 B000000 Y
026 C000000 N
<PAGE> PAGE 4
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 Y
028 A010000 7909
028 A020000 0
028 A030000 0
028 A040000 2214
028 B010000 8120
028 B020000 0
028 B030000 0
028 B040000 3236
028 C010000 6022
028 C020000 0
028 C030000 0
028 C040000 2407
028 D010000 4791
028 D020000 378
028 D030000 0
028 D040000 1228
028 E010000 4376
028 E020000 0
028 E030000 0
028 E040000 3305
028 F010000 4383
028 F020000 0
028 F030000 0
028 F040000 4096
028 G010000 35601
028 G020000 378
028 G030000 0
028 G040000 16486
028 H000000 35536
029 000000 Y
030 A000000 31
030 B000000 5.25
030 C000000 0.00
031 A000000 0
031 B000000 5
032 000000 0
033 000000 36
034 000000 Y
035 000000 161
036 A000000 N
036 B000000 0
037 000000 N
038 000000 0
039 000000 N
<PAGE> PAGE 5
040 000000 Y
041 000000 Y
042 A000000 0
042 B000000 0
042 C000000 100
042 D000000 0
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 550
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.600
048 A010000 0
048 A020000 0.000
048 B010000 0
048 B020000 0.000
048 C010000 0
048 C020000 0.000
048 D010000 0
048 D020000 0.000
048 E010000 0
048 E020000 0.000
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 0
048 K020000 0.000
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 Y
053 B000000 Y
054 A000000 Y
054 B000000 Y
054 C000000 Y
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 N
<PAGE> PAGE 6
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 Y
054 M000000 Y
054 N000000 N
054 O000000 Y
055 A000000 Y
055 B000000 N
056 000000 Y
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 Y
060 B000000 Y
061 000000 1000
062 A000000 N
062 B000000 0.0
062 C000000 0.0
062 D000000 0.0
062 E000000 0.0
062 F000000 0.0
062 G000000 0.0
062 H000000 0.0
062 I000000 0.0
062 J000000 0.0
062 K000000 0.0
062 L000000 0.0
062 M000000 0.0
062 N000000 0.0
062 O000000 0.0
062 P000000 0.0
062 Q000000 0.0
062 R000000 0.0
063 A000000 0
063 B000000 0.0
066 A000000 Y
066 B000000 N
066 C000000 N
066 D000000 N
066 E000000 N
066 F000000 N
066 G000000 Y
067 000000 N
068 A000000 N
068 B000000 N
069 000000 Y
070 A010000 Y
070 A020000 Y
070 B010000 N
<PAGE> PAGE 7
070 B020000 N
070 C010000 N
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 N
070 E020000 N
070 F010000 Y
070 F020000 Y
070 G010000 N
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 N
070 J020000 N
070 K010000 Y
070 K020000 N
070 L010000 Y
070 L020000 N
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 N
070 O020000 N
070 P010000 Y
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 30855
071 B000000 80074
071 C000000 104617
071 D000000 8
072 A000000 6
072 B000000 136
072 C000000 681
072 D000000 0
072 E000000 0
072 F000000 340
072 G000000 0
072 H000000 0
072 I000000 95
072 J000000 17
072 K000000 0
072 L000000 0
072 M000000 9
072 N000000 23
<PAGE> PAGE 8
072 O000000 0
072 P000000 0
072 Q000000 0
072 R000000 10
072 S000000 9
072 T000000 550
072 U000000 77
072 V000000 0
072 W000000 6
072 X000000 1136
072 Y000000 0
072 Z000000 -319
072AA000000 1229
072BB000000 1384
072CC010000 6278
072CC020000 0
072DD010000 0
072DD020000 0
072EE000000 416
073 A010000 0.0000
073 A020000 0.0000
073 B000000 0.1788
073 C000000 0.0000
074 A000000 0
074 B000000 0
074 C000000 3903
074 D000000 0
074 E000000 0
074 F000000 113697
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 0
074 K000000 20
074 L000000 397
074 M000000 131
074 N000000 118148
074 O000000 0
074 P000000 162
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 195
074 S000000 0
074 T000000 117791
074 U010000 8732
074 U020000 724
074 V010000 0.00
074 V020000 0.00
074 W000000 0.0000
<PAGE> PAGE 9
074 X000000 10582
074 Y000000 6739
075 A000000 0
075 B000000 112658
076 000000 0.00
077 A000000 N
078 000000 N
080 C000000 0
081 B000000 0
082 B000000 0
083 B000000 0
084 B000000 0
086 A010000 0
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
SIGNATURE BARRY FINK
TITLE VICE PRESIDENT
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
Morgan Stanley Dean Witter S&P 500 Select Fund
Semi-Annual FDS Class D
August 31, 1999
</LEGEND>
<CIK> 0001063265
<NAME> MSDw S&P 500 SELECT FUND - CLASS D
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> FEB-29-2000
<PERIOD-END> AUG-31-1999
<INVESTMENTS-AT-COST> 102,732,768
<INVESTMENTS-AT-VALUE> 117,600,342
<RECEIVABLES> 396,955
<ASSETS-OTHER> 150,663
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 118,147,960
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> (357,268)
<TOTAL-LIABILITIES> (357,268)
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 103,388,561
<SHARES-COMMON-STOCK> 22,461
<SHARES-COMMON-PRIOR> 17,196
<ACCUMULATED-NII-CURRENT> (319,186)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (40,984)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 14,762,341
<NET-ASSETS> 281,852
<DIVIDEND-INCOME> 681,192
<INTEREST-INCOME> 135,707
<OTHER-INCOME> 0
<EXPENSES-NET> (1,136,085)
<NET-INVESTMENT-INCOME> (319,186)
<REALIZED-GAINS-CURRENT> (155,123)
<APPREC-INCREASE-CURRENT> 6,277,695
<NET-CHANGE-FROM-OPS> 5,803,386
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (910)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 5,245
<NUMBER-OF-SHARES-REDEEMED> (34)
<SHARES-REINVESTED> 54
<NET-CHANGE-IN-ASSETS> 24,880,786
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 529,681
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> (339,820)
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> (1,136,085)
<AVERAGE-NET-ASSETS> 247,998
<PER-SHARE-NAV-BEGIN> 11.79
<PER-SHARE-NII> 0.03
<PER-SHARE-GAIN-APPREC> 0.91
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.18)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 12.55
<EXPENSE-RATIO> 1.03
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
Morgan Stanley Dean Witter S&P 500 Select Fund
Semi-Annual FDS Class C
August 31, 1999
</LEGEND>
<CIK> 0001063265
<NAME> MSDW S&P 500 SELECT FUND - CLASS C
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> FEB-29-2000
<PERIOD-END> AUG-31-1999
<INVESTMENTS-AT-COST> 102,732,768
<INVESTMENTS-AT-VALUE> 117,600,342
<RECEIVABLES> 396,955
<ASSETS-OTHER> 150,663
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 118,147,960
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> (357,268)
<TOTAL-LIABILITIES> (357,268)
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 103,388,561
<SHARES-COMMON-STOCK> 701,206
<SHARES-COMMON-PRIOR> 545,412
<ACCUMULATED-NII-CURRENT> (319,186)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (40,984)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 14,762,341
<NET-ASSETS> 8,735,258
<DIVIDEND-INCOME> 681,192
<INTEREST-INCOME> 135,707
<OTHER-INCOME> 0
<EXPENSES-NET> (1,136,085)
<NET-INVESTMENT-INCOME> (319,186)
<REALIZED-GAINS-CURRENT> (155,123)
<APPREC-INCREASE-CURRENT> 6,277,695
<NET-CHANGE-FROM-OPS> 5,803,386
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (29,852)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 234,101
<NUMBER-OF-SHARES-REDEEMED> (80,625)
<SHARES-REINVESTED> 2,318
<NET-CHANGE-IN-ASSETS> 24,880,786
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 529,681
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> (339,820)
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> (1,136,085)
<AVERAGE-NET-ASSETS> 8,024,356
<PER-SHARE-NAV-BEGIN> 11.77
<PER-SHARE-NII> (0.04)
<PER-SHARE-GAIN-APPREC> 0.91
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.18)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 12.46
<EXPENSE-RATIO> 2.03
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
Morgan Stanley Dean Witter S&P 500 Select Fund
Semi-Annual FDS Class B
August 31, 1999
</LEGEND>
<CIK> 0001063265
<NAME> MSDW S&P 500 SELECT FUND - CLASS B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> FEB-29-2000
<PERIOD-END> AUG-31-1999
<INVESTMENTS-AT-COST> 102,732,768
<INVESTMENTS-AT-VALUE> 117,600,342
<RECEIVABLES> 396,955
<ASSETS-OTHER> 150,663
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 118,147,960
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> (357,268)
<TOTAL-LIABILITIES> (357,268)
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 103,388,561
<SHARES-COMMON-STOCK> 8,392,621
<SHARES-COMMON-PRIOR> 7,057,210
<ACCUMULATED-NII-CURRENT> (319,186)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (40,984)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 14,762,341
<NET-ASSETS> 104,529,058
<DIVIDEND-INCOME> 681,192
<INTEREST-INCOME> 135,707
<OTHER-INCOME> 0
<EXPENSES-NET> (1,136,085)
<NET-INVESTMENT-INCOME> (319,186)
<REALIZED-GAINS-CURRENT> (155,123)
<APPREC-INCREASE-CURRENT> 6,277,695
<NET-CHANGE-FROM-OPS> 5,803,386
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (368,750)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 2,447,930
<NUMBER-OF-SHARES-REDEEMED> (1,139,108)
<SHARES-REINVESTED> 26,589
<NET-CHANGE-IN-ASSETS> 24,880,786
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 529,681
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> (339,820)
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> (1,136,085)
<AVERAGE-NET-ASSETS> 100,312,406
<PER-SHARE-NAV-BEGIN> 11.76
<PER-SHARE-NII> (0.04)
<PER-SHARE-GAIN-APPREC> 0.91
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.18)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 12.45
<EXPENSE-RATIO> 2.03
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
Morgan Stanley Dean Witter S&P 500 Select Fund
Semi-Annual FDS Class A
August 31, 1999
</LEGEND>
<CIK> 0001063265
<NAME> MSDW S&P 500 SELECT FUND - CLASS A
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> FEB-29-2000
<PERIOD-END> AUG-31-1999
<INVESTMENTS-AT-COST> 102,732,768
<INVESTMENTS-AT-VALUE> 117,600,342
<RECEIVABLES> 396,955
<ASSETS-OTHER> 150,663
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 118,147,960
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> (357,268)
<TOTAL-LIABILITIES> (357,268)
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 103,388,561
<SHARES-COMMON-STOCK> 338,845
<SHARES-COMMON-PRIOR> 277,358
<ACCUMULATED-NII-CURRENT> (319,186)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (40,984)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 14,762,341
<NET-ASSETS> 4,244,564
<DIVIDEND-INCOME> 681,192
<INTEREST-INCOME> 135,707
<OTHER-INCOME> 0
<EXPENSES-NET> (1,136,085)
<NET-INVESTMENT-INCOME> (319,186)
<REALIZED-GAINS-CURRENT> (155,123)
<APPREC-INCREASE-CURRENT> 6,277,695
<NET-CHANGE-FROM-OPS> 5,803,386
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (16,030)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 147,088
<NUMBER-OF-SHARES-REDEEMED> (86,714)
<SHARES-REINVESTED> 1,113
<NET-CHANGE-IN-ASSETS> 24,880,786
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 529,681
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> (339,820)
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> (1,136,085)
<AVERAGE-NET-ASSETS> 4,073,029
<PER-SHARE-NAV-BEGIN> 11.79
<PER-SHARE-NII> 0.01
<PER-SHARE-GAIN-APPREC> 0.91
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> (0.18)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 12.53
<EXPENSE-RATIO> 1.28
</TABLE>