This study was performed to investigate the effects of Eunwhasagantang and Eunwhasagantangganokyong on the viability of tumor cells in vitro(MTT assay), on antitumor effects after Sarcoma-180 cells transplantation into the peritoneal cavity or left groin, and on decreased immune responses in mice induced by methotrexate. The extracts of its herbal medicines were orally administered for 14 or 21 days. To evaluate the effects of the Eunwhasagantang and Eunwhasagantangganokyong many items such as 50% inhibitory concentration($IC_{50}$), mean survival days, tumor and body weight for antitumor effects, and delayed type hypersensitivity, hemagglutinin titer, hemolysin titer, rosette forming cells, natural killer cell activity, lymphocyte transformation, productivity of interleukin-2 and phagocytic activity for immune responses were measured in ICR mice. The results were obtained as follows; 1. $IC_{50}$ of Eunwhasagantang treated group was 0.000204mg/ml on SNU-396 and that of Eunwhasagantangganokyong treated group was 0.000103mg／ml on SNU-1, those results indicate that the medicine has high antitumor activity. 2. Mean survival times in Eunwhasagantang and Eunwhasagantangganokyong treated groups were slightly increased with no significance, as compared with the control group. 3. Tumor weight in Eunwhasagantang and Eunwhasagantangganokyong treated group was depressed, as compared with the control group(p<0.01). 4. Body weight in Eunwhasagantang and Eunwhasagantangganokyong treated group was significantly increased, as compared with the control group(p<0.05). 5. Delayed type hypersensitivity in Eunwhasagantang and Eunwhasagantang-ganokyong treated group was slightly decreased with no significance, as compared with the control group. 6. Hemagglutinin titer in Eunwhasagantang and Eunwhasagantangganokyong treated group was slightly increased with no significance, as compared with the control group. 7. Hemolysin titer only in Eunwhasagantang treated group was significantly increased, as compared with the control group(p<0.01). 8. Rosette forming cells only in Eunwhasagantangganokyong treated group was slightly increased with no significance, as compared with the control group. 9. In the NK cell activity, the ratio of effector cells and target cells of the Eunwhasagantang treated group was significantly increased(p<0.01) in case which the ratio was 100: 1, and that of the Eunwhasagantangganokyong treated group was significantly increased(P<.01, p<0.05) in case which the ratio was 100:1, 50:1, as compared with the control group. 10. Lymphocyte trasnformation in Eunwhasagantang and Eunwhasagantangganokyong treated group was significantly increased, as compared with the control group(p<0.01). 11. Interleukin-2 in Eunwhasagantang and Eunwhasagantangganokyong treated group was significantly increased, as compared with the control group(p<0.05, p<0.01). 12. Phagocytic activity in Eunwhasagantang and Eunwhasagantangganokyong treated group was significantly increased, as compared with the control group(p<0.05). According to the above results, it could be suggested that Eunwhasagantang and Eunwhasagantangganokyong have prominent antitumor effects, and enhance both cellular and humoral immunity.