Objective: To investigate the effects of clomiphene combined low dose aspirin on endometrium development of anovulation patients. Methods: 120 cases of anovulation patients were randomly divided into study group and control group with 60 patients in each group. The patients in control group were only treated with clomiphene, while the patients in study group were treated with clomiphene combined low dose aspirin. The pregnancy rate in ovulation cycle, HCG day endometrial thickness and endometrial type of patients in 2 groups were compared. Results: There was no significant differences between the two groups about pregnancy rate in ovulation cycle (43.33% vs 36.67%), HCG day endometrial thickness and endometrial type (P＞0.05). Conclusions: Treating anovulation patients with clomiphene combined low dose aspirin can improve the pregnancy rate to a certain degree, but the improving effects on endometrium development are not obvious.