Abstract: Objective To observe the effects of marine peote in peptide(MPP)combined with nucleotides(NT)on mimunnom odulation in mice and its possible mechanism.Methods Female Balb/c mice(6-8 weeks old,n=160)were administered with MPP and NT for 4 weeks at the doses of 0.795,0.265,and 0.088 g/kg·bw,respectively.Cell-mediated mimune function,humoral mimune function,phagocytic function of mononuclear phagocyte,NK cell activity,the level of mimuno globulin in serum were detected and the splenocyte subpopulaions were determined with flow cytomter.Results The capacity of lymphoyte proliferation(0.25·0.03)induced by Con A,D TH response(0.34·0.04 mm)in the low dose group(0.088 g/kg·bw)of comb ination were significantly increased compared with that of control group(P<0.05).IgMPFC number of the low dose group(2.08·0.11)was significantly higher than that of control group(P<0.05).The percentage of CD4⁺T cell and the ratio of CD4⁺/CD8⁺ in spleen of the low dose group(35.45·0.97%,2.20·0.18%)were higher than those of in control guoup(P<0.05).The level of serum IgG(115.82·11.06),IgM(45.91·632)and IgA (12.49·0.75)in the low dose guoup were significantly increased compared with that of comtrol guoup(P<0.05).Conclusion MPP combined with NT could improve the mimune function in mice.