To observe the clinical effect of modified Shuyu tang combined with femonston for infertility with kidney-yang deficiency syndrome caused by thin endometrium.Methods：Selected 76 cases of patients with infertility with kidney-yang deficiency syndrome caused by thin endometrium and divided them into the control group and the treatment group according to the random number table，with 38 cases in each group.Both groups were treated with femonston tablets，while the treatment group was additionally given the oral administration of modified Shuyu tang.Both groups received the treatment for 3 menstrual cycles.Compared the Chinese medicine syndrome scores，endometrial thickness and the levels of serum estradiol(E2)in the two groups before and after treatment，and recorded the pregnancy rate within one year of follow-up.Results： After treatment， the scores of dizziness and tinnitus， soreness and weakness of waist and knees，aversion to cold and abdominal coldness，libido apathy and frequent urination in the two groups were all lower than those before treatment(P ＜ 0.01)，and the scores of the five scores mentioned above in the treatment group were lower than those in the control group(P ＜ 0.01).After treatment，endometrial thickness and the levels of E2in both groups were increased when compared with those before treatment(P ＜ 0.01)，and the increase of endometrial thickness and level of E2in the treatment group was much more significant than that in the control group(P＜0.01).During the one year of follow-up after treatment， the pregnancy rate was 57.89% in the treatment group and 31.58% in the control group， difference being significant in the comparison of the two groups(P＜0.05).Conclusion：The application of modified Shuyu tang combined with femonston for infertility with kidney-yang deficiency syndrome caused by thin endometrium can effectively improve the Chinese medicine syndromes of patients， increase the endometrial thickness， increase the of levels E2and improve pregnancy rate.