Purpose　The aim is to investigate the effects of BSP on immunological function in normal and immunosuppressed mices.Methods　Thymus and spleen indexes, peripheral blood WBC number,the lymphocyte proliferation response, IL-2 production and serum and splenocyte hemolysin contents were measured after intraperitoneal injection of BSP in normal and immunosuppressed mices.Results　(1)BSP 100 mg/（kg*d）×10d significantly increased the thymus and spleen indexes and peripheral blood WBC number in immunosuppressed mice.The thymus and spleen indexes in normal mice was also increased. In addition,BSP markedly improved T,B lymphocyte proliferation responses and IL-2 production in normal and immunosupressed mices.(2) BSP improved the serum and splenocyte hemolysin contents in normal and immunosuppressed mice. Conclusion　It was suggested that BSP was a kind of immunomodulator, and could improve the immunological function of normal and immunosuppressed mices.