In order to investigate the effects of Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang on antitumor effects after Sarcoma-180 cells transplantation into the peritoneal cavity or left groin in mice, and immune responses in mice induced by methotrexate, the extracts of its herbal medicines were orally administered for 14 or 21 days. Experimental studies were performed for measurance of 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 and phagocytic activity for immune responses in ICR mice. Following results were obtained : 1. Mean survival time in Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang-treated group was significantly prolonged, as compared with the control group(P<0.010, P<0.005). 2. Tumor weight in Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang-treated group was significantly depressed, as compared with the control group(P<0.050, P<0.050). 3. Body weight in Banhabaekchulcheonmatang-treated group was significantly increased (P<0.050), but in Banhabackchulcheonmatanggamibang-treated group was slightly increased with no effectivenes, as compared with the control group. 4. Delayed type hypersensitivity in Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang-treated group was significantly increased, as compared with the control group(P<0.010, P<0.050). 5. Hemagglutinin titer in Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang-treated group was significantly increased, as compared with the control group(P<0.050, P<0.050). 6. Hemolysin titer in Banhabaekchulcheonmatanggamibang-treated group was significantly increased (P<0.050), but in Banhabaekchulcheonmatanggamibang-treated group was slightly increased with no effectiveness, as compared with the control group. 7. Rosette forming cells in Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang-treated group was slightly increased with no effectiveness, as compared with the control group. 8. Natural Killer cell activity in Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang-treated group was slightly increased with no effectiveness, as compared with the control group. 9. Phagocytic activity in Banhabaekchulcheonmatanggamibang-treated group group was significantly increased (P<0.050), but in Banhabaekchulcheonmatanggamibang-treated group was increased with no effectiveness, as compared with the control group. According to the above results, it could be suggested that Banhabaekchulcheonmatang and Banhabaekchulcheonmatanggamibang have prominent antitumor effects, and enhance both cellular and humoral immunity.