These studies were designed to determine the potential cytotoxic activity of MeOH extracts of 65 crude drugs against leukemia L1210 and $P388D_1$, cell line in vitro, of which 25 samples were selected. The n-BuOH extracts of 25 samples were measured using the same method and nine were selected. These samples were measured for the potential antitumor activity against $P388D_1$, for life span in vivo, and against sarcoma 180 for tumor weight. On the basis of results, Notoginseng Radix, Anemarrhenae Rhizoma, Albizziae Cortex, Portulacae Herba, Bupleuri Radix were evaluated the effective plant on the antitumor activity. In addition, the mixture of Notoginseng Radix and Albizziae Cortex was evaluated to enhance the antitumor activity in vivo.