Abstract: Objective:To explore the regulation effects of low molecular weight peptide of colla corii asini(LMWPC)on immunomodulatory in mice. Methods:The protein content and molecular weight distribution of LMWPC were analyzed by kjeldahl method and high-performance gel chromatography. The effects of LMWPC(0.18,0.35 and 1.05 g/kg·bw)on humoral immunity of mice were investigated using the rite of blood serum hemolysin and hemolytic antibody. The delayed hypersensitivity and the blastisation of spleen lymphocyte were used to study the effects of LMWPC on cell-mediated immunity of mice. Results:Compared with the control group,the molecular weight of LMWPC,which was rich in protein(88.84±1.77 g/100 g),was mainly below 1000 Da,the half hemolysis value(HC₅₀)of high dose group was(76.8±4.2)(P<0.05),toes swelling was(0.35±0.03) mm(P<0.05),OD value of mouse spleen lymphocyte transformation test was(0.344±0.052)(P<0.05). Compared with the low and medium dose group,high dose group had the best ability to increase serum hemolysin level in mice,enhance the delayed hypersensitivity and promote the proliferation of splenic lymphocytes. However,LMWPC in the medium dose group could significantly increase the antibody production of mice spleen cells. Conclusion:LMWPC could effectively enhance cell-mediated and humoral immune responses in mice. In this study,LMWPC could improve the humoral immunity and cell-mediated immunity of mice,and had a positive regulatory effect on the immune functions.