<PAGE> PAGE 1
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<PAGE> PAGE 2
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<PAGE> PAGE 3
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<PAGE> PAGE 4
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<PAGE> PAGE 6
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<PAGE> PAGE 9
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<PAGE> PAGE 10
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<PAGE> PAGE 11
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SIGNATURE DANA R. SUTTON
TITLE VP & TREASURER
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
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WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
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<LEGEND>
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<NAME> AIM INVESTMENT SECURITES FUNDS, INC.
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<PER-SHARE-DIVIDEND> (0.90)
<PER-SHARE-DISTRIBUTIONS> (0.01)
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 11.25
<EXPENSE-RATIO> 1.00
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information from the AIM High
Yield II Fund Class B Shares July 31, 1999 annual report.
</LEGEND>
<CIK> 0000842790
<NAME> AIM INVESTMENT SECURITES FUNDS, INC.
<SERIES>
<NUMBER> 3
<NAME> AIM HIGH YIELD II FUND CLASS B SHARES
<S> <C>
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<FISCAL-YEAR-END> JUL-31-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 56050006
<INVESTMENTS-AT-VALUE> 57406269
<RECEIVABLES> 5071111
<ASSETS-OTHER> 54260
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 62531640
<PAYABLE-FOR-SECURITIES> 2894450
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 512285
<TOTAL-LIABILITIES> 3406735
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 56098289
<SHARES-COMMON-STOCK> 5259608
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<ACCUMULATED-NII-CURRENT> 3310
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<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 1356263
<NET-ASSETS> 59124905
<DIVIDEND-INCOME> 7952
<INTEREST-INCOME> 2498346
<OTHER-INCOME> 0
<EXPENSES-NET> (275240)
<NET-INVESTMENT-INCOME> 2231058
<REALIZED-GAINS-CURRENT> 1689995
<APPREC-INCREASE-CURRENT> 1356263
<NET-CHANGE-FROM-OPS> 5277316
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (2227748)
<DISTRIBUTIONS-OF-GAINS> (22952)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 6358522
<NUMBER-OF-SHARES-REDEEMED> (1226122)
<SHARES-REINVESTED> 127208
<NET-CHANGE-IN-ASSETS> 59124905
<ACCUMULATED-NII-PRIOR> 0
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<AVERAGE-NET-ASSETS> 7499236
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<PER-SHARE-NII> 0.68
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<PER-SHARE-DIVIDEND> (0.68)
<PER-SHARE-DISTRIBUTIONS> (0.01)
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 11.23
<EXPENSE-RATIO> 1.75
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
This schedule contains summary financial information from the AIM High
Yield II Fund Class C Shares July 31, 1999 annual report.
</LEGEND>
<CIK> 0000842790
<NAME> AIM INVESTMENT SECURITES FUNDS, INC.
<SERIES>
<NUMBER> 3
<NAME> AIM HIGH YIELD II FUND CLASS C SHARES
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> JUL-31-1999
<PERIOD-END> JUL-31-1999
<INVESTMENTS-AT-COST> 56050006
<INVESTMENTS-AT-VALUE> 57406269
<RECEIVABLES> 5071111
<ASSETS-OTHER> 54260
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 62531640
<PAYABLE-FOR-SECURITIES> 2894450
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 512285
<TOTAL-LIABILITIES> 3406735
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 56098289
<SHARES-COMMON-STOCK> 5259608
<SHARES-COMMON-PRIOR> 0
<ACCUMULATED-NII-CURRENT> 3310
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 1667043
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 1356263
<NET-ASSETS> 59124905
<DIVIDEND-INCOME> 7952
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<EXPENSES-NET> (275240)
<NET-INVESTMENT-INCOME> 2231058
<REALIZED-GAINS-CURRENT> 1689995
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<NUMBER-OF-SHARES-SOLD> 6358522
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<NET-CHANGE-IN-ASSETS> 59124905
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<PER-SHARE-NAV-END> 11.22
<EXPENSE-RATIO> 1.75
</TABLE>
