Abstract: To investigate the immune regulative and protective effect of Yupingfeng polysaccharides (YPF-P) on immunosuppressive mice, the immunosuppressive mouse model was induced by cyclophosphamide (80 mg/kg), and the changes of spleen index, spleen lymphocyte proliferation, serum hemolysin and serum IL-2 were observed in the study. The results showed that YPF- P could improve the spleen index of immunosuppressive mice, to promote the spleen lymphocyte proliferation. YPF- P can promote hemolysin antibody in the serum of normal mice, against serum hemolysin antibody reduction of mice caused by cyclophosphamide reduced, YPF-P could improve the normal mice and immunosuppressive mice serum levels of IL- 2, especially in middle and low dose group. Those results confirmed that YPF- P could resist the immunosuppression of mice induced by cyclophosphamide, and improve immune function and protect the function of spleen.