Abstract: Objective To explore the effect of Heshouwuyin on the expression of cytochrome C oxidase7a2(Cox7a2) in testis tissue of rats with exercised-induced fatigue. Methods Fifty SD rats were divided into normal control group (A group), Heshouwuyin administered normal group (B group), model control group (C group), Heshouwuyin treated group (D group) and Heshouwuyin prevented group (E group) randomly with 10 rats for each. The exercise-induced fatigue models in rats of C, D, E groups were established. The rats in D group were treated with Heshouwuyin20 g/(kg·d), contained crude drug 9.6 g/mL for 60 days (during the 42 days of modeling and after the 18 days of modeling). The rats in E group were also treated with Heshouwuyin for 60 days (but before the 18 days of modeling and during the 42 days of modeling). Beckmancoulter Unicel Dxl 800 was used to detect the level of serum testosterone, according to the manufacture's instructions. Western blot and RT-PCR were used to observe the differential expression of Cox7a2. Results The level of serum testosterone in C group was decreased compared with A group (P<0.05), which implied the success of modeling. Compared with group A, the level of serum testosterone in B, D, E groups were increased (P<0.05). Cox7a2 protein was expressed mainly in leydig cell and spermatocyte. Compared with A,B, D, E groups, the expression of Cox7a2 protein and mRNA in C group increased (P<0.05), and there no significant difference was observed between group A and B, as well as group D and E. Conclusion The expression of Cox7a2 was down-regulated by Heshouwuyin.