<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000862501
<NAME> Institutional High Yield Bond Fund
<SERIES>
<NUMBER>001
<NAME>Salomon Brothers Institutional Series Funds Inc.
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> Feb-28-2001
<PERIOD-END> Aug-31-2000
<INVESTMENTS-AT-COST> 37,817,447
<INVESTMENTS-AT-VALUE> 30,842,084
<RECEIVABLES> 757,504
<ASSETS-OTHER> 8,988
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 31,608,576
<PAYABLE-FOR-SECURITIES> 256,172
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 24,717
<TOTAL-LIABILITIES> 280,889
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 39,169,012
<SHARES-COMMON-STOCK> 4,193,784
<SHARES-COMMON-PRIOR> 6,769,075
<ACCUMULATED-NII-CURRENT> 3,184,147
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (4,050,109)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (6,975,363)
<NET-ASSETS> 31,327,687
<DIVIDEND-INCOME> 14,300
<INTEREST-INCOME> 2,511,844
<OTHER-INCOME> 0
<EXPENSES-NET> 123,047
<NET-INVESTMENT-INCOME> 2,403,097
<REALIZED-GAINS-CURRENT> (1,779,351)
<APPREC-INCREASE-CURRENT> (1,434,053)
<NET-CHANGE-FROM-OPS> (810,307)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 2,201,621
<NUMBER-OF-SHARES-REDEEMED> 4,776,912
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> (20,086,983)
<ACCUMULATED-NII-PRIOR> 781,050
<ACCUMULATED-GAINS-PRIOR> (2,270,758)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 111,861
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 189,497
<AVERAGE-NET-ASSETS> 44,379,557
<PER-SHARE-NAV-BEGIN> 7.600
<PER-SHARE-NII> 0.430
<PER-SHARE-GAIN-APPREC> (0.560)
<PER-SHARE-DIVIDEND> 0.000
<PER-SHARE-DISTRIBUTIONS> 0.000
<RETURNS-OF-CAPITAL> 0.000
<PER-SHARE-NAV-END> 7.470
<EXPENSE-RATIO> 0.55
</TABLE>