The aim of this study was to investigate the immuno-regulatory effects of pea peptides on immunosuppressive mice. Mice injected with cyclophosphamide(CTX)was the model group and normal saline was the control group. Different dosages of pea peptide(0.4 g/(kg·bw)，0.8 g/(kg·bw)，1.6 g/(kg·bw)were given to low，middle and high groups for 15 days. The body weight, spleen, and thymus weight of mice，morphologic variations of immune organs，white blood cell count，T lymphocyte subsets of spleen，immunoglobulin content，cytokine levels, bone marrow nucleated cell count and DNA content were tested. The morphological changes of spleen and thymus were observed under microscope in the model group. The number of white blood cell，proportion of CD3+，CD4+，CD8+ T lymphocyte，concentration of immunoglobulin IgG and IgM, and nucleated cell counts and DNA density in bone marrow were significantly lower than the control group (p<0.01). The concentration of IFN-γ was significantly lower than that of the control group (p<0.05). Compared with the model group, pea peptide groups showed different degrees of improvement in the above indicators. Pea peptide can improve the immune function of immunosuppressive mice induced by CTX.