Abstract: Protein was extracted from fresh frozen Oviductus Ranae by ammonium sulfate grade precipitation combined with ultrasonic treatment.Oviductus Ranae protein hydrolysate was prepared with neutral protease.Effect of Oviductus Ranae, Oviductus Ranae protein and neutral protease hydrolysate of Oviductus Ranae protein on functions of spleen lymphocyte and macrophage were investigated by testing proliferation of spleen lymphocyte, Interleukin-2 ( IL-2) secretion of spleen lymphocyte, phagocytic function of macrophage and NO production.These results showed Oviductus Ranae, Oviductus Ranae protein and neutral protease hydrolysate of Oviductus Ranae protein promoted immune functions of spleen lymphocyte and macrophage, and the neutral protease hydrolysate of Oviductus Ranae protein showed the most significant effect to improve immunefunctions ( increased the proliferation of spleen lymphocyte, IL- 2 secretion by spleen lymphocyte, macrophage phagocytosis and NO production by macrophages to 19.3%, 104.8%, 109.1% and 34.9%, respectively) . These results suggested that neutral protease hydrolyzate of Oviductus Ranae protein could promote the immune functions of spleen lymphocyte and macrophage significantly ( p < 0.01) .