Abstract: 【Objective】 The purpose of this experiment is to study the effects of adding different proportions of cotton stalks on the production performance, serum related hormones and testicular tissues of the reserve ram. 【Method】 The experiment used a single factor completely randomized trial design, and randomly divided 60 small-tailed Han sheep baCKup breed of similar weight into 6 groups, 10 in each group.The diet of control group 1 (group CK₁) did not contain cotton source feed,and control group 2 (group CK₂) contained cotton seed meal and without cotton stalk.On the basis of CK₂ diet,the trial group diet was supplemented with 20% (group A),30% (group B),40% (group C) and 50% (group D) cotton stalks.The full duration of the trial was 70 days, including a preliminary trial period of 10 days and a formal trial period of 60 days. 【Results】 (1)there were no significant differences in dry matter intake, daily gain and feed meat ratio between CK₁ and CK₂ groups (P>0.05); dry matter intake of group D was significantly higher than that of CK₂ group by 17.80% (P<0.01), extremely significantly higher than that of group A and C by 18.42% (P<0.01) and 16.58% (P<0.01), and significantly higher than that of group B by 4.65% (P<0.05); the daily gain and feed / meat ratio of group A, B, C, D and CK₂ were also different.There was no significant difference (P>0.05).(2) There was no significant difference in serum testosterone and gossypol between the experimental group and the control group (P> 0.05).(3) The growth and development of testes in the control group and the experimental group were normal without pathological injury. 【Conclusion】 The addition of 20% -50% cotton stalks to diet does not affect the production performance of reserve ram, serum related hormones and testicular growth and development, and 20% cotton stalks are the best.