The water extract of Gamidaebo-Tang depressed the lethal toxicity of cis-platin$(45{mu}M/kg,;s.c.)$, and mitomycin C (6mg/kg, s.c.). Significant depression of renal toxicity(indicated by an increased blood urea nitrogen value and creatinine value) of cis-platin $(35{mu}M/kg);s.c.)$, was observed in mice treated with Gamidaebo-Tang. In rats treated with mitomycin C and Gamidaebo-Tang, the increased LDH activity and reduced total protein and albumin contents by mitomycin C were significantly depressed. The number of WBC was significantly increased in rats treated with mitomycin C but in the rats treated with mitomycin C and Gamidaebo-Tang, the number of WBC was increased and the hematocrit value and the number of RBC and Hgb were significantly increased in the dose-dependent manner. Therefore, bone marrow toxicity of mitomycin C in the rats treated with Gamidaebo-Tang was depressed. In the end, alleviative effects of the side actions of cis-platin and mitomycin C were acknowledged by combined usage of Gamidaebo-Tang and these anti-neoplastic drugs.