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<PAGE> PAGE 4
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<PAGE> PAGE 5
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<PAGE> PAGE 6
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<PAGE> PAGE 10
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<PAGE> PAGE 11
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<PAGE> PAGE 12
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SIGNATURE DANA R. SUTTON
TITLE SR. V.P. & TREASURER
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
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<NAME> AIM INVESTMENT SECURITIES FUNDS
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WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
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<LEGEND>
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January 31, 2000, semi-annual report.
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<CIK> 0000842790
<NAME> AIM INVESTMENT SECURITIES FUNDS
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WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information for the
AIM High Yield II Fund, Class B shares, January 31, 2000,
semi-annual report.
</LEGEND>
<CIK> 0000842790
<NAME> AIM INVESTMENT SECURITIES FUNDS
<SERIES>
<NUMBER> 3
<NAME> AIM HIGH YIELD II FUND, CLASS B SHARES
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUL-31-2000
<PERIOD-END> JAN-31-2000
<INVESTMENTS-AT-COST> 99531822
<INVESTMENTS-AT-VALUE> 102165421
<RECEIVABLES> 3786067
<ASSETS-OTHER> 36157
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 105987645
<PAYABLE-FOR-SECURITIES> 4852443
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 669563
<TOTAL-LIABILITIES> 5522006
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 98811011
<SHARES-COMMON-STOCK> 9101692
<SHARES-COMMON-PRIOR> 5259608
<ACCUMULATED-NII-CURRENT> 187098
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (1166069)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 2633599
<NET-ASSETS> 100465639
<DIVIDEND-INCOME> 47606
<INTEREST-INCOME> 4271606
<OTHER-INCOME> 0
<EXPENSES-NET> (509033)
<NET-INVESTMENT-INCOME> 3810179
<REALIZED-GAINS-CURRENT> (1083047)
<APPREC-INCREASE-CURRENT> 1277336
<NET-CHANGE-FROM-OPS> 4004468
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (3059254)
<DISTRIBUTIONS-OF-GAINS> (1750071)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 6559530
<NUMBER-OF-SHARES-REDEEMED> (3059254)
<SHARES-REINVESTED> 341808
<NET-CHANGE-IN-ASSETS> 41340734
<ACCUMULATED-NII-PRIOR> 20746
<ACCUMULATED-GAINS-PRIOR> 1667049
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 236529
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 643174
<AVERAGE-NET-ASSETS> 32341556
<PER-SHARE-NAV-BEGIN> 11.23
<PER-SHARE-NII> 0.52
<PER-SHARE-GAIN-APPREC> 0.02
<PER-SHARE-DIVIDEND> (0.51)
<PER-SHARE-DISTRIBUTIONS> (0.23)
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 11.03
<EXPENSE-RATIO> 1.75
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule conains summary financial information for the
AIM High Yield II Fund, Class C shares, January 31, 2000,
semi-annual report.
</LEGEND>
<CIK> 0000842790
<NAME> AIM INVESTMENT SECURITIES FUNDS
<SERIES>
<NUMBER> 3
<NAME> AIM HIGH YIELD II FUND, CLASS C SHARES
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUL-31-2000
<PERIOD-END> JAN-31-2000
<INVESTMENTS-AT-COST> 99531822
<INVESTMENTS-AT-VALUE> 102165421
<RECEIVABLES> 3786067
<ASSETS-OTHER> 36157
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 105987645
<PAYABLE-FOR-SECURITIES> 4852443
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 669563
<TOTAL-LIABILITIES> 5522006
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 98811011
<SHARES-COMMON-STOCK> 9101692
<SHARES-COMMON-PRIOR> 5259608
<ACCUMULATED-NII-CURRENT> 187098
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (1166069)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 2633599
<NET-ASSETS> 100465639
<DIVIDEND-INCOME> 47606
<INTEREST-INCOME> 4271606
<OTHER-INCOME> 0
<EXPENSES-NET> (509033)
<NET-INVESTMENT-INCOME> 3810179
<REALIZED-GAINS-CURRENT> (1083047)
<APPREC-INCREASE-CURRENT> 1277336
<NET-CHANGE-FROM-OPS> 4004468
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (3643827)
<DISTRIBUTIONS-OF-GAINS> (1750071)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 6559530
<NUMBER-OF-SHARES-REDEEMED> (3059254)
<SHARES-REINVESTED> 341808
<NET-CHANGE-IN-ASSETS> 41340734
<ACCUMULATED-NII-PRIOR> 20746
<ACCUMULATED-GAINS-PRIOR> 1667049
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 236529
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 643174
<AVERAGE-NET-ASSETS> 4836068
<PER-SHARE-NAV-BEGIN> 11.22
<PER-SHARE-NII> 0.52
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<PER-SHARE-DIVIDEND> (0.51)
<PER-SHARE-DISTRIBUTIONS> (0.23)
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 11.02
<EXPENSE-RATIO> 1.75
</TABLE>
