Abstract: Kinds of chemotherapeutic drugs often used mere studied by 3H-TdR releaseassays to detect their effects on IL-2/LAK activity. The results showed that:different chemotherapeutic drugs's effects on IL-2/LAK activity was different, and different concentrations of the same chemotherapeutic drug's was different also. Carbo/CDDP had no inhibitory effects on induction of LAK activity by IL-2, and couldaccelarate the lysis activity of LAK cell; CTX/5-Fu had no inhibitory effects onIL-2/LAK activity; But ADM/MMC had inhibitory effects on IL-2/LAK activity.These suggested that: Carbo/CDDP combined with IL-2/LAK in cancer treatmentmay have cooperations; CTX/5-Fu combined with IL-2/LAK may have plus actions; But ADM/MMC may reduce LAK activity.