Objective:To study the effects of the blueberry on immune modulation in rats. Methods:Rats were orally administered with blueberry extract and sterile water for 30 days at the dose of 54 mg,108 mg and 325 mg/(kg·bw). Weight,index of immune organs,proliferation ability of lymphocytes,DTH response,the level of serum HC50,NK cell activity and phagocytic function of macrophages were observed. Results:Compared with the control group,the blueberry could improve the capacities of lymphocyte proliferation induced by ConA,DTH response,the level of serum HC50,NK cell activity and macrophage in group of 325 mg/kg. It could improve DTH response and the level of serum HC50 in group of 108 mg/kg. And it could improve NK cell activity in group of 54 mg/kg. Conclusion:Blueberry has effects on promoting immune function in rats.