Ethanol, total saponin and petroleum ether extract of Panax ginseng C.A. Meyer were tested for their anticlastogenic effects against induction of micronuclei by cyclophosphamide and benzo(a)pyrene in mice. Ginseng petroleum ether extract (GPEE) showed the highest suppressive effect among three extracts. GPEE was also tested to compare their anticlastogenic effect against several well-known carcinogens: such as mitomycin C, 7, 12-dimethyl benzo(a)anthracene, ethyl methane sulfonate, dimethylnitrosamine and busulfan. GPEE showed the anticlastogenic effect against most of carcinogens, although there were no significant effects against 7, 12-dimethyl benzo(a) anthracene, dimethyl nitrosoamine and busulfan-induced micronuclei.