To identify antitumor materials, oriental herb extracts were investigated in the present study. The effects of individual oriental herb extracts (OHE) and a mixture of these extracts (MOHE) for antioxidant, free radical scavenging, and tumoricidal activities were determined. The OHEs and MOHE exhibited relatively high free radical scavenging and antioxidant activities, in a concentration dependent manner. The total phenolic contents of the extracts suggest that these compounds may have played a role, at least in part, in the free radical scavenging and antioxidant effects. Since the MOHE showed the highest toxicity against tumor cell lines, the MOHE was administrated in cancer mice models. Consistent with the in vitro studies, the MOHE resulted in prolonged life spans in cancer mice possibly by combination of its anticancer and antioxidant activities. Our data indicate the possibilities of using the MOHE to counteract carcinogenesis as well as other forms of electrophilic toxicity.