[ARTICLE] 6
[CIK] 0000910068
[NAME] HIGH INCOME OPPORTUNITY FUND INC.
<TABLE>
<S>                             <C>
[PERIOD-TYPE]                   6-MOS
[FISCAL-YEAR-END]                          SEP-30-1999
[PERIOD-END]                               MAR-31-1999
[INVESTMENTS-AT-COST]                      814,036,630
[INVESTMENTS-AT-VALUE]                     794,504,487
[RECEIVABLES]                               21,389,690
[ASSETS-OTHER]                                       0
[OTHER-ITEMS-ASSETS]                                 0
[TOTAL-ASSETS]                             815,894,177
[PAYABLE-FOR-SECURITIES]                     6,859,025
[SENIOR-LONG-TERM-DEBT]                              0
[OTHER-ITEMS-LIABILITIES]                    2,750,833
[TOTAL-LIABILITIES]                          9,609,858
[SENIOR-EQUITY]                                      0
[PAID-IN-CAPITAL-COMMON]                   899,841,149
[SHARES-COMMON-STOCK]                       72,230,352
[SHARES-COMMON-PRIOR]                       72,016,610
[ACCUMULATED-NII-CURRENT]                  (1,613,943)
[OVERDISTRIBUTION-NII]                               0
[ACCUMULATED-NET-GAINS]                   (72,635,336)
[OVERDISTRIBUTION-GAINS]                             0
[ACCUM-APPREC-OR-DEPREC]                  (19,307,551)
[NET-ASSETS]                               806,284,319
[DIVIDEND-INCOME]                              391,627
[INTEREST-INCOME]                           42,733,646
[OTHER-INCOME]                                       0
[EXPENSES-NET]                               4,839,847
[NET-INVESTMENT-INCOME]                     38,285,426
[REALIZED-GAINS-CURRENT]                  (15,556,829)
[APPREC-INCREASE-CURRENT]                    9,537,321
[NET-CHANGE-FROM-OPS]                       32,265,918
[EQUALIZATION]                                       0
[DISTRIBUTIONS-OF-INCOME]                   37,901,912
[DISTRIBUTIONS-OF-GAINS]                             0
[DISTRIBUTIONS-OTHER]                                0
[NUMBER-OF-SHARES-SOLD]                              0
[NUMBER-OF-SHARES-REDEEMED]                          0
[SHARES-REINVESTED]                            213,742
[NET-CHANGE-IN-ASSETS]                       2,293,455
[ACCUMULATED-NII-PRIOR]                    (1,966,392)
[ACCUMULATED-GAINS-PRIOR]                 (57,109,572)
[OVERDISTRIB-NII-PRIOR]                              0
[OVERDIST-NET-GAINS-PRIOR]                           0
[GROSS-ADVISORY-FEES]                        4,624,337
[INTEREST-EXPENSE]                                   0
[GROSS-EXPENSE]                              4,839,847
[AVERAGE-NET-ASSETS]                       197,253,156
[PER-SHARE-NAV-BEGIN]                            11.24
[PER-SHARE-NII]                                  00.53
[PER-SHARE-GAIN-APPREC]                         (0.08)
[PER-SHARE-DIVIDEND]                             00.53
[PER-SHARE-DISTRIBUTIONS]                            0
[RETURNS-OF-CAPITAL]                                 0
[PER-SHARE-NAV-END]                              11.16
[EXPENSE-RATIO]                                  01.20
[AVG-DEBT-OUTSTANDING]                               0
[AVG-DEBT-PER-SHARE]                                 0
</TABLE>