Chemoprevetive effect of Saururus Chinensis (Lour.) Bail water extract on several tumor cells and Chinese hamster V79 cells were investigated. The water extracts of Saururus Chinensis (Lour.) Bail showed a higher cytotoxicity effect on the human histiocytic leukemia cells(U937) and protective effects against the cytotoxicity of HO. These results suggest that Saururus Chinensis (Lour.) Bail may useful as potential soures of chemopreventive and antioxidative agents.