Objective : Jeungson-Ojeok-Hwan Bijukbang(JOH) has been used to treat patients with tumor etc. In the theory of Korean medicine, JOH can treat Juk-Chui. JOH is known to have treat Juk-Chui. Juk-Chui is analogous to tumor. Methods : For these reasons, the present study was designed to investigate the effects of JOH on solid tumor in mice in terms of immune-potentiating and direct cytotoxic action of JOH in vitro and vivo study. The present author investigated thymocyte and splenocyte proliferation to confirm immune-potentiating activity of JOH and also investigated tumor/body weight ratio and survival rates in tumor bearing mice. Results : In this study, administration of JOH decreased tumor/body weight ratio significantly, and prolonged survival duration compared to non-treated control. In addition, treatment with JOH suppressed proliferation rate of Sarcoma 180 (S-180) cells significantly, and elevated proliferation rates of thymocytes isolated from normal mice. These results were co-related with in vivo study. Conclusion : these results suggest that JOH is useful to treat patient with solid tumor, because JOH has direct toxic action for tumor cell and immune-potentiating action for T cells. Further study will need to elucidate exact mechanisms related in anti-cancer action of JOH.