This study was performed to determine the cytotoxic effect of methanol extract from medicinal plants. 1. The cell viability was determined by MTT method. Their cytotoxic activities against three cancer cell lines such as A549, MDA-MB-231 and SNU-C4 cell line were tested. 2. Among them, The methanol extract of Saururus Ohinensis Bail showed the strongest cytotoxic effect against SNU-C4 cells. These results suggest that the methanol extract of Saururus Ohinensis Bail possessed a potential antitumorous agent. 3. The free radical scavenging activity using DPPH method was the strongest of Saururus Chinensis Bail extract.