<TABLE> <S> <C>

<ARTICLE> 6
<CIK> 0000862502
<NAME> Salomon Brothers Institutional Money Market Fund
<SERIES>
   <NUMBER>003
   <NAME>Salomon Brothers Investment Series Funds Inc

<S>                             <C>
<PERIOD-TYPE>                  6-MOS
<FISCAL-YEAR-END>                               Dec-31-2000
<PERIOD-END>                                    Jun-30-2000
<INVESTMENTS-AT-COST>                           131,513,146
<INVESTMENTS-AT-VALUE>                          131,513,146
<RECEIVABLES>                                       804,760
<ASSETS-OTHER>                                            0
<OTHER-ITEMS-ASSETS>                                      0
<TOTAL-ASSETS>                                  132,317,906
<PAYABLE-FOR-SECURITIES>                                  0
<SENIOR-LONG-TERM-DEBT>                                   0
<OTHER-ITEMS-LIABILITIES>                           816,493
<TOTAL-LIABILITIES>                                 816,493
<SENIOR-EQUITY>                                           0
<PAID-IN-CAPITAL-COMMON>                        131,502,566
<SHARES-COMMON-STOCK>                           131,502,566
<SHARES-COMMON-PRIOR>                           119,232,128
<ACCUMULATED-NII-CURRENT>                               881
<OVERDISTRIBUTION-NII>                                    0
<ACCUMULATED-NET-GAINS>                              (2,034)
<OVERDISTRIBUTION-GAINS>                                  0
<ACCUM-APPREC-OR-DEPREC>                                  0
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<DIVIDEND-INCOME>                                         0
<INTEREST-INCOME>                                 3,826,373
<OTHER-INCOME>                                            0
<EXPENSES-NET>                                      110,676
<NET-INVESTMENT-INCOME>                           3,715,697
<REALIZED-GAINS-CURRENT>                                  0
<APPREC-INCREASE-CURRENT>                                 0
<NET-CHANGE-FROM-OPS>                             3,715,697
<EQUALIZATION>                                            0
<DISTRIBUTIONS-OF-INCOME>                         3,715,697
<DISTRIBUTIONS-OF-GAINS>                                  0
<DISTRIBUTIONS-OTHER>                                     0
<NUMBER-OF-SHARES-SOLD>                          50,919,503
<NUMBER-OF-SHARES-REDEEMED>                      41,167,979
<SHARES-REINVESTED>                               2,518,914
<NET-CHANGE-IN-ASSETS>                           12,270,438
<ACCUMULATED-NII-PRIOR>                                 881
<ACCUMULATED-GAINS-PRIOR>                            (2,034)
<OVERDISTRIB-NII-PRIOR>                                   0
<OVERDIST-NET-GAINS-PRIOR>                                0
<GROSS-ADVISORY-FEES>                               153,911
<INTEREST-EXPENSE>                                        0
<GROSS-EXPENSE>                                     217,657
<AVERAGE-NET-ASSETS>                            122,338,649
<PER-SHARE-NAV-BEGIN>                                 1.000
<PER-SHARE-NII>                                       0.030
<PER-SHARE-GAIN-APPREC>                               0.000
<PER-SHARE-DIVIDEND>                                  0.030
<PER-SHARE-DISTRIBUTIONS>                             0.000
<RETURNS-OF-CAPITAL>                                  0.000
<PER-SHARE-NAV-END>                                   1.000
<EXPENSE-RATIO>                                        0.36



</TABLE>