<PAGE> PAGE 1
000 B000000 07/31/97
000 C000000 842790
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 U
001 A000000 AIM INVESTMENT SECURITIES FUNDS
001 B000000 811-5686
001 C000000 7136261919
002 A000000 ELEVEN GREENWAY PLAZA, SUITE 100
002 B000000 HOUSTON
002 C000000 TX
002 D010000 77046
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
007 B000000 2
007 C010100 1
007 C010200 2
007 C020200 LIMITED MATURITY TREASURY INSTIT. SHARES
007 C030200 N
007 C010300 3
007 C020300 AIM LIMITED MATURITY TREASURY SHARES
007 C030300 N
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A00AA01 AIM ADVISORS, INC.
008 B00AA01 A
008 C00AA01 801-12313
008 D01AA01 HOUSTON
008 D02AA01 TX
008 D03AA01 77046
008 D04AA01 1173
013 A00AA01 KPMG PEAT MARWICK LLP
013 B01AA01 HOUSTON
013 B02AA01 TX
013 B03AA01 77002
015 A00AA01 BANK OF NEW YORK
015 B00AA01 C
015 C01AA01 NEW YORK
015 C02AA01 NY
<PAGE> PAGE 2
015 C03AA01 10286
015 E01AA01 X
018 00AA00 Y
019 A00AA00 Y
019 B00AA00 39
019 C00AA00 AIMFUNDSAA
022 A000001 FIRST BOSTON CORP. (THE)
022 B000001 13-5659485
022 C000001 79935
022 D000001 56804
022 A000002 SALOMON BROTHERS INC.
022 B000002 13-3082694
022 C000002 75101
022 D000002 61476
022 A000003 MENDHAM CAPITAL GROUP, INC.
022 B000003 22-3165996
022 C000003 76944
022 D000003 33811
022 A000004 UBS SECURITIES INC.
022 B000004 13-2932996
022 C000004 62436
022 D000004 45362
022 A000005 CITICORP SECURITIES MARKETS INC.
022 B000005 13-4994650
022 C000005 45386
022 D000005 52447
022 A000006 MORGAN STANLEY & CO. INC.
022 B000006 13-2655998
022 C000006 48959
022 D000006 38819
022 A000007 PAINE WEBBER INC.
022 B000007 13-2638166
022 C000007 20113
022 D000007 58909
022 A000008 DONALDSON, LUFKIN & JENRETTE SECURITIES CORP.
022 B000008 13-2741729
022 C000008 36423
022 D000008 42176
022 A000009 GOLDMAN, SACHS & CO.
022 B000009 13-5108880
022 C000009 37922
022 D000009 21501
022 A000010 SMITH BARNEY INC.
022 B000010 13-1912900
022 C000010 24582
022 D000010 32855
023 C000000 548531
023 D000000 615465
024 00AA00 N
026 A000000 N
026 B000000 N
<PAGE> PAGE 3
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 Y
045 00AA00 Y
046 00AA00 N
047 00AA00 Y
048 00AA00 0.000
048 A01AA00 500000
048 A02AA00 0.200
048 B01AA00 0
048 B02AA00 0.000
048 C01AA00 0
048 C02AA00 0.000
048 D01AA00 0
048 D02AA00 0.000
048 E01AA00 0
048 E02AA00 0.000
048 F01AA00 0
048 F02AA00 0.000
048 G01AA00 0
048 G02AA00 0.000
048 H01AA00 0
048 H02AA00 0.000
048 I01AA00 0
048 I02AA00 0.000
048 J01AA00 0
048 J02AA00 0.000
048 K01AA00 500000
048 K02AA00 0.175
049 00AA00 N
050 00AA00 N
051 00AA00 N
052 00AA00 N
053 A00AA00 N
054 A00AA00 Y
054 B00AA00 N
054 C00AA00 N
054 D00AA00 N
054 E00AA00 N
054 F00AA00 N
054 G00AA00 N
054 H00AA00 Y
054 I00AA00 N
054 J00AA00 Y
054 K00AA00 N
054 L00AA00 N
<PAGE> PAGE 4
054 M00AA00 Y
054 N00AA00 N
054 O00AA00 N
062 A00AA00 Y
062 B00AA00 0.0
062 C00AA00 0.0
062 D00AA00 0.0
062 E00AA00 0.0
062 F00AA00 0.0
062 G00AA00 0.0
062 H00AA00 0.0
062 I00AA00 0.0
062 J00AA00 0.0
062 K00AA00 0.0
062 L00AA00 0.0
062 M00AA00 99.0
062 N00AA00 0.0
062 O00AA00 0.0
062 P00AA00 0.0
062 Q00AA00 0.0
062 R00AA00 0.0
063 A00AA00 0
063 B00AA00 1.5
064 A00AA00 N
066 A00AA00 N
067 00AA00 N
068 A00AA00 N
068 B00AA00 N
069 00AA00 N
070 A01AA00 Y
070 A02AA00 N
070 B01AA00 N
070 B02AA00 N
070 C01AA00 N
070 C02AA00 N
070 D01AA00 N
070 D02AA00 N
070 E01AA00 N
070 E02AA00 N
070 F01AA00 N
070 F02AA00 N
070 G01AA00 N
070 G02AA00 N
070 H01AA00 N
070 H02AA00 N
070 I01AA00 N
070 I02AA00 N
070 J01AA00 N
070 J02AA00 N
070 K01AA00 Y
070 K02AA00 N
<PAGE> PAGE 5
070 L01AA00 N
070 L02AA00 N
070 M01AA00 N
070 M02AA00 N
070 N01AA00 Y
070 N02AA00 N
070 O01AA00 Y
070 O02AA00 N
070 P01AA00 Y
070 P02AA00 N
070 Q01AA00 N
070 Q02AA00 N
070 R01AA00 N
070 R02AA00 N
077 A000000 Y
077 B000000 Y
077 Q010000 Y
078 000000 N
080 A00AA00 ICI MUTUAL INSURANCE CO.
080 C00AA00 25000
081 A00AA00 Y
081 B00AA00 80
082 A00AA00 Y
082 B00AA00 100
083 A00AA00 N
083 B00AA00 0
084 A00AA00 N
084 B00AA00 0
085 A00AA00 N
085 B00AA00 N
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
011 A000201 FUND MANAGEMENT COMPANY (FMC)
011 B000201 8-41848
011 C010201 HOUSTON
011 C020201 TX
011 C030201 77046
012 A000201 AIM INSTITUTIONAL FUND SERVICES, INC.
012 B000201 84-5541
012 C010201 HOUSTON
012 C020201 TX
<PAGE> PAGE 6
012 C030201 77046
028 A010200 78
028 A020200 3
028 A030200 0
028 A040200 8096
028 B010200 2540
028 B020200 4
028 B030200 0
028 B040200 397
028 C010200 2133
028 C020200 4
028 C030200 0
028 C040200 124
028 D010200 340
028 D020200 4
028 D030200 0
028 D040200 565
028 E010200 2352
028 E020200 4
028 E030200 0
028 E040200 332
028 F010200 6484
028 F020200 0
028 F030200 0
028 F040200 354
028 G010200 13927
028 G020200 19
028 G030200 0
028 G040200 9868
028 H000200 0
029 000200 N
030 A000200 0
030 B000200 0.00
030 C000200 0.00
034 000200 N
035 000200 0
036 B000200 0
037 000200 N
038 000200 0
039 000200 N
040 000200 N
055 A000200 N
055 B000200 N
056 000200 N
057 000200 N
058 A000200 N
059 000200 Y
060 A000200 Y
060 B000200 Y
061 000200 1000000
071 A000200 548531
<PAGE> PAGE 7
071 B000200 615465
071 C000200 422798
071 D000200 130
072 A000200 12
072 B000200 3072
072 C000200 0
072 D000200 0
072 E000200 0
072 F000200 105
072 G000200 0
072 H000200 0
072 I000200 5
072 J000200 4
072 K000200 0
072 L000200 13
072 M000200 1
072 N000200 0
072 O000200 0
072 P000200 0
072 Q000200 8
072 R000200 3
072 S000200 3
072 T000200 0
072 U000200 0
072 V000200 0
072 W000200 17
072 X000200 159
072 Y000200 0
072 Z000200 2913
072AA000200 110
072BB000200 151
072CC010200 597
072CC020200 0
072DD010200 2913
072DD020200 0
072EE000200 0
073 A010200 0.5594
073 A020200 0.0000
073 B000200 0.0000
073 C000200 0.0000
074 A000200 2
074 B000200 0
074 C000200 0
074 D000200 48395
074 E000200 0
074 F000200 0
074 G000200 0
074 H000200 0
074 I000200 0
074 J000200 0
074 K000200 0
<PAGE> PAGE 8
074 L000200 707
074 M000200 11
074 N000200 49115
074 O000200 0
074 P000200 10
074 Q000200 0
074 R010200 0
074 R020200 0
074 R030200 0
074 R040200 239
074 S000200 0
074 T000200 48866
074 U010200 4854
074 U020200 0
074 V010200 10.07
074 V020200 0.00
074 W000200 0.0000
074 X000200 17
074 Y000200 0
075 A000200 0
075 B000200 56861
076 000200 0.00
011 A000301 AIM DISTRIBUTORS, INC.
011 B000301 8-21323
011 C010301 HOUSTON
011 C020301 TX
011 C030301 77046
012 A000301 AIM FUNDS SERVICES, INC.
012 B000301 84-5432
012 C010301 HOUSTON
012 C020301 TX
012 C030301 77210
012 C040301 4739
028 A010300 15161
028 A020300 1251
028 A030300 0
028 A040300 16052
028 B010300 25259
028 B020300 1425
028 B030300 0
028 B040300 17930
028 C010300 14986
028 C020300 1379
028 C030300 0
028 C040300 20203
028 D010300 10566
028 D020300 1419
028 D030300 0
028 D040300 14729
028 E010300 14302
028 E020300 1381
<PAGE> PAGE 9
028 E030300 0
028 E040300 13965
028 F010300 41071
028 F020300 1238
028 F030300 0
028 F040300 22562
028 G010300 121345
028 G020300 8093
028 G030300 0
028 G040300 105441
028 H000300 16543
029 000300 Y
030 A000300 341
030 B000300 1.00
030 C000300 0.00
031 A000300 106
031 B000300 0
032 000300 235
033 000300 0
034 000300 N
035 000300 0
036 B000300 0
037 000300 N
038 000300 0
039 000300 N
040 000300 Y
041 000300 Y
042 A000300 0
042 B000300 0
042 C000300 100
042 D000300 0
042 E000300 0
042 F000300 0
042 G000300 0
042 H000300 0
043 000300 550
044 000300 0
055 A000300 N
055 B000300 N
056 000300 N
057 000300 N
058 A000300 N
059 000300 Y
060 A000300 Y
060 B000300 Y
061 000300 500
071 A000300 548531
071 B000300 615465
071 C000300 422798
071 D000300 130
072 A000300 12
<PAGE> PAGE 10
072 B000300 21582
072 C000300 0
072 D000300 0
072 E000300 0
072 F000300 733
072 G000300 0
072 H000300 0
072 I000300 337
072 J000300 31
072 K000300 0
072 L000300 88
072 M000300 10
072 N000300 0
072 O000300 0
072 P000300 0
072 Q000300 59
072 R000300 20
072 S000300 21
072 T000300 550
072 U000300 0
072 V000300 0
072 W000300 125
072 X000300 1974
072 Y000300 5
072 Z000300 19613
072AA000300 770
072BB000300 1058
072CC010300 4178
072CC020300 0
072DD010300 19613
072DD020300 0
072EE000300 0
073 A010300 0.5360
073 A020300 0.0000
073 B000300 0.0000
073 C000300 0.0000
074 A000300 19
074 B000300 0
074 C000300 0
074 D000300 386027
074 E000300 0
074 F000300 0
074 G000300 0
074 H000300 0
074 I000300 0
074 J000300 0
074 K000300 0
074 L000300 5637
074 M000300 92
074 N000300 391775
074 O000300 0
<PAGE> PAGE 11
074 P000300 129
074 Q000300 0
074 R010300 0
074 R020300 0
074 R030300 0
074 R040300 1836
074 S000300 0
074 T000300 389810
074 U010300 38719
074 U020300 0
074 V010300 10.07
074 V020300 0.00
074 W000300 0.0000
074 X000300 14700
074 Y000300 0
075 A000300 0
075 B000300 367133
076 000300 0.00
SIGNATURE JOHN J. ARTHUR
TITLE SR. V.P. & TRESURER
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information for the Institutional
Shares of the Limited Maturity Treasury Portfolio for the year ended July 31, 1997.
</LEGEND>
<CIK> 0000842790
<NAME> AIM INVESTMENT SECURITIES FUNDS
<SERIES>
<NUMBER> 002
<NAME> LIMITED MATURITY TREASURY INSTITUTIONAL SHARES
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> JUL-31-1997
<PERIOD-END> JUL-31-1997
<INVESTMENTS-AT-COST> 431928484
<INVESTMENTS-AT-VALUE> 434422415
<RECEIVABLES> 6343699
<ASSETS-OTHER> 123934
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 440890048
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2212825
<TOTAL-LIABILITIES> 2212825
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 443515589
<SHARES-COMMON-STOCK> 43572323
<SHARES-COMMON-PRIOR> 50399269
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (7332297)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 2493931
<NET-ASSETS> 438677223
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 24654293
<OTHER-INCOME> 0
<EXPENSES-NET> (2128383)
<NET-INVESTMENT-INCOME> 22525910
<REALIZED-GAINS-CURRENT> (328964)
<APPREC-INCREASE-CURRENT> 4775213
<NET-CHANGE-FROM-OPS> 26972159
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (22525910)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 25459367
<NUMBER-OF-SHARES-REDEEMED> (33903093)
<SHARES-REINVESTED> 1616780
<NET-CHANGE-IN-ASSETS> (63838582)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (7003333)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 837760
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2133546
<AVERAGE-NET-ASSETS> 52373873
<PER-SHARE-NAV-BEGIN> 9.97
<PER-SHARE-NII> .56
<PER-SHARE-GAIN-APPREC> .10
<PER-SHARE-DIVIDEND> (.56)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 10.07
<EXPENSE-RATIO> .31
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information for the AIM Limited
Maturity Treasury Shares of the Limited Maturity Treasury Portfolio for
the year ended July 31, 1997.
</LEGEND>
<CIK> 0000842790
<NAME> AIM INVESTMENT SECURITIES FUNDS
<SERIES>
<NUMBER> 003
<NAME> AIM LIMITED MATURITY TREASURY SHARES
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> JUL-31-1997
<PERIOD-END> JUL-31-1997
<INVESTMENTS-AT-COST> 431928484
<INVESTMENTS-AT-VALUE> 434422415
<RECEIVABLES> 6343699
<ASSETS-OTHER> 123934
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 440890048
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2212825
<TOTAL-LIABILITIES> 2212825
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 443515589
<SHARES-COMMON-STOCK> 43572323
<SHARES-COMMON-PRIOR> 50399269
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (7332297)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 2493931
<NET-ASSETS> 438677223
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 24654293
<OTHER-INCOME> 0
<EXPENSES-NET> (2128383)
<NET-INVESTMENT-INCOME> 22525910
<REALIZED-GAINS-CURRENT> (328964)
<APPREC-INCREASE-CURRENT> 4775213
<NET-CHANGE-FROM-OPS> 26972159
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (22525910)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 25459367
<NUMBER-OF-SHARES-REDEEMED> (33903093)
<SHARES-REINVESTED> 1616780
<NET-CHANGE-IN-ASSETS> (63838582)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (7003333)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 837760
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2133546
<AVERAGE-NET-ASSETS> 366506207
<PER-SHARE-NAV-BEGIN> 9.97
<PER-SHARE-NII> .54
<PER-SHARE-GAIN-APPREC> .10
<PER-SHARE-DIVIDEND> (.54)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 10.07
<EXPENSE-RATIO> .54
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
