The methanol extracts prepared from ten kinds of culinary herbs were investigated for the cytotoxcic effect againt L1210 cancer cells and the mode of action. The substantial cytotoxic effects were observed in all cases with the most prominent effect demonstrated by lemon verbena extract showing 87±4.1 % cytotoxicity with 100㎍/ml concentration and 3 days culture period. The cytotoxic effect was found to be dose and culture period dependent. With respect to the mechanism of the cytotoxicity, the augmented generation of O_2^-ion and the dramatically escalated activities of antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroixidase (GPx) with addition of the herb methanol extracts suggested that there would be the involvement of reactive oxygen species (ROS) metabolism in the course of L1210 cancer cell death by the methanol extract of the edible herbs.