Objective:To observe the effect of lycium barbarum polysaccharide (LBP)on the reproductive damage of hypoandrogen male sterile rats,and to evaluate the efficacy and possible mechanism of LBP in the treatment of hypoandrogen male sterility. MethodsMale adult SD rats were randomly divided into blank control group,model control group,low-dose and high-dose LBP group. The model was made by intragastric administration of dutasteride 40 mg / kg once a day for 28 days,and LBP was given by gavage at the 15th day of modeling. LBP 80 mg / kg and 40 mg / kg were given in the high-dose and the low-dose LBP groups respectively and the model control group was given the same amount of vehicle for 14 days. At the end of administration,testicular and epididymal histology, ultrastructure, sperm activity,pregnancy rate,serum androgen level,epididymal androgen receptor (AR)and nuclear factor kappa-B (NF-κB)protein were detected.  Results:compared with the model control group,the sperm viability and forward movement rate in the high-dose LBP group were significantly higher (P＜0.05). The pregnancy rate was 37.5% and 62.5% in the low-dose and the high-dose LBP group,respectively,which was 25% and 50% higher than that in the model control group. The epididymal epithelial junction was broken and sperms gathered in the epididymis in the model control group. The epididymal epithelial structure and sperm arrangement were recovered to a certain extent in the low-dose LBP group and the epididymal epithelium and sperms in the high-dose LBP group basically recovered to normal. The serum dihydrotestosterone(DHT) in the both LBP groups was significantly higher than that in model control group (P＜0.05,P＜0.01); the expression of AR and NF-κB protein in the both LBP groups was significantly higher than that in model control group(P＜0.05,P＜0.01).  Conclusion:LBP can improve the fertility of hypoandrogenic epididymal infertility rats,which may be related to the increase of serum DHT level,the promotion of AR and NF-κB expression and the exertion of androgen like activity.