Background : Gamisamryungbaekchul-san(加味蔘?白朮散) is a herbal medicine which has been used for the traditional therapeutic agent of augmentation of the spleen and reinforcement of the Qi. Objective : This Study was performed to investigate the effect of Gamisamryungbaekchul-san on the tumor and immune response in the moose B16 melanoma tumor model. Materials and Methods : The tumor was induced by subcutaneous inoculation of B16BL6 melanoma cells in the shaved dorsal region of mice. Mice were orally administered with Gamisamryungbaekchul-san extract(26.3mg/mouse) for 14days after inoculation. For making examination of antitumor effect, the Increase of life span, Tumor growth inhibition rate, change of body weight were measured and evaluated. For the immune response increasing effect, the percentage of T lymphocyte and B Lymphocyte in the peripheral blood, the percentage of CD4+ T-cell, CD8+ T-cell and CD4+/CD8+ ratio in the peripheral blood and spleen, interleukin-2 productivity were measured and evaluated. Results : Gamisamryungbaekchul-san showed 16.59% increase of life span, 31.64% tumor growth inhibition rate and increase of body weight. Gamisamryungbaekchul-san increased the percentage of T lymphocyte in the peripheral blood, CD4+ T cell percentage of peripheral blood and spleen, and Interleukin-2 productivity as compared with the Control group. Whereas Gamisamryungbaekchul-san had no effect on the percentage of B lymphocyte in the peripheral blood, the percentage of CD8+ T cell, CD4+/CD8+ T-cell ratio in both of peripheral blood and spleen as compared with the Control group. Conclusion : This study shows that Gamisamryungbaekchul-san has anti-tumor effects and immunoregulatory effects on the B16 melanoma tumor model. It is suggested that Gamisarmyungbaekchul-san could be a useful immunomodulator and anti-tumor agent.