Objective To explore the effect of Heshouwuyin on the expression of 17β-hydroxysteroid dehydrogenase (17β-HSD) in testis tissue of exercise-induced fatigue rats. Methods Fifty SD rats were divided randomly into 5 groups, each group had 10 rats including normal control group(A group), Heshouwuyin administered normal group(B group), model control group(C group), Heshouwuyin treated group (D group), Heshouwuyin prevented group (E group). The rats in the C, D and E groups were made exerciseinduced fatigue animal model, and animals were administrated heshouwuyin［20g/(kgI>&#/I>8226;d),contained crude drug 9.6kg/L］, with the exception of E group, animals in E group were administrated heshouwuyin before modeling. The D group was treated with Heshouwuyin by intragastric administration for 60 days after success of modeling. The blood serum concentration of testosterone was detected by radioimmunity, and immunohistochemistry method, Western blotting and RT-PCR were used to observe the differential expression of 17β-HSD. Results 17β-HSD protein expressed in Leydig cells. Compared with C group, the expressions of 17β-HSD protein and mRNA in D, E groups increased (EM>P/EM>0.05)