[ARTICLE] 6
[CIK] 0000355747
[NAME] SMITH BARNEY INVESTMENT FUNDS INC.
[SERIES]
   [NUMBER] 1
   [NAME] SB INVESTMENT GRADE BOND FUND, CLASS B
<TABLE>
<S>                             <C>
[PERIOD-TYPE]                   YEAR
[FISCAL-YEAR-END]                          DEC-31-1997
[PERIOD-END]                               DEC-31-1997
[INVESTMENTS-AT-COST]                      487,794,677
[INVESTMENTS-AT-VALUE]                     540,822,710
[RECEIVABLES]                               10,100,680
[ASSETS-OTHER]                                       0
[OTHER-ITEMS-ASSETS]                                 0
[TOTAL-ASSETS]                             550,253,525
[PAYABLE-FOR-SECURITIES]                             0
[SENIOR-LONG-TERM-DEBT]                              0
[OTHER-ITEMS-LIABILITIES]                      669,865
[TOTAL-LIABILITIES]                            669,865
[SENIOR-EQUITY]                                      0
[PAID-IN-CAPITAL-COMMON]                   493,135,684
[SHARES-COMMON-STOCK]                       19,370,001
[SHARES-COMMON-PRIOR]                       21,027,741
[ACCUMULATED-NII-CURRENT]                            0
[OVERDISTRIBUTION-NII]                         398,245
[ACCUMULATED-NET-GAINS]                        446,324
[OVERDISTRIBUTION-GAINS]                             0
[ACCUM-APPREC-OR-DEPREC]                    53,028,033
[NET-ASSETS]                               550,253,525
[DIVIDEND-INCOME]                                    0
[INTEREST-INCOME]                           36,173,355
[OTHER-INCOME]                                       0
[EXPENSES-NET]                               6,060,112
[NET-INVESTMENT-INCOME]                     30,113,243
[REALIZED-GAINS-CURRENT]                       490,877
[APPREC-INCREASE-CURRENT]                   46,515,710
[NET-CHANGE-FROM-OPS]                       77,119,830
[EQUALIZATION]                                       0
[DISTRIBUTIONS-OF-INCOME]                   14,596,014
[DISTRIBUTIONS-OF-GAINS]                     5,191,085
[DISTRIBUTIONS-OTHER]                                0
[NUMBER-OF-SHARES-SOLD]                      2,694,477
[NUMBER-OF-SHARES-REDEEMED]                  5,862,166
[SHARES-REINVESTED]                          1,037,967
[NET-CHANGE-IN-ASSETS]                      61,022,455
[ACCUMULATED-NII-PRIOR]                     30,913,830
[ACCUMULATED-GAINS-PRIOR]                   17,850,048
[OVERDISTRIB-NII-PRIOR]                          7,345
[OVERDIST-NET-GAINS-PRIOR]                           0
[GROSS-ADVISORY-FEES]                        2,183,438
[INTEREST-EXPENSE]                                   0
[GROSS-EXPENSE]                              6,060,112
[AVERAGE-NET-ASSETS]                       249,344,112
[PER-SHARE-NAV-BEGIN]                            12.29
[PER-SHARE-NII]                                  00.75
[PER-SHARE-GAIN-APPREC]                          01.18
[PER-SHARE-DIVIDEND]                             00.75
[PER-SHARE-DISTRIBUTIONS]                        00.28
[RETURNS-OF-CAPITAL]                                 0
[PER-SHARE-NAV-END]                              13.19
[EXPENSE-RATIO]                                  01.51
[AVG-DEBT-OUTSTANDING]                               0
[AVG-DEBT-PER-SHARE]                                 0
</TABLE>