This paper has shown the cytocidal effects of alcohol extracts of roots and rhizomes of Sinopodophyllum emodi (Wall.) Ying on human erythroleukemia K562 cells, leukemia L1210 cells, leukemia L7712 cells in vitro, using microculture method for 24 hours. The survival rates on K562 cells in the final concentrations of 10.0, 5.0, 2.5, 1.0 micrograms/ml of the extracts of Sinopodophyllum emodi (WA11.) Ying were 44.17%, 47.63%, 64.43%, 79.57% respectively. The survival rates on L1210 and L7712 cells were 42.84%, 50.73%, 63.21%, 75.10%, and 39.76%, 46.36%, 61.42%, 75.24% respectively. LD50 of the extracts singly i.p. in mice was 76.3-60.6 mg/kg. In vivo, the growth of transplanted mouse tumours (EAC, U14 and Hc) was inhibited by the extracts of Sinopodophyllum emodi (Wall.) Ying with inhibitory rates 42.2%, 38.8%, 41.5% (14.0 mg/kg); 37.8%, 33.3%, 35.6% (7.0 mg/kg).