Matrine also inhibited the growth of Ehrlich ascites carcinoma in mice. Sophocarpine moderately inhibited the transplanted tumors S180, U14, Lio-1. W256 and L615. RNA and DNA contents in Ehrlich ascites tumor cells in mice were decreased by 7-9% and 20-30%, respectively, following administration of 60-120 mg/kg of socrocarpine. Sococarpine treatment also reduced the incorporation of 3H-thymidine into tumor cell DNA by 21-34%. Matrine showed immunosuppressive activity. Murine spleen cell proliferation and IL-2 formation were decreased by 50% in culture at fairly high concentrations of 0.1 and 0.6 mg/ml, respectively. Sophocarpine did not show effect on immune activity in mice.