Abstract: Objective  To explore the effective of Dingkundan on thin endometrium in the clomiphene induced ovulation cycle, and provide basis for clinical practice. Methods  A total of 127 patients who visited department of gynecological endocrinology, with thin endometrium in clomiphene induced ovulation cycle were recruited. Patients were randomly assigned to the control group and the experimental group based on the principle of ensuring basic feature comparable between groups. A total of 64 patients in experimental group were treated with Dingkun Pill+ estrodiol, while a total of 63 patients in control group were treated with estrodiol. The endometrial thickness and type on human chorionic gonadotropin（hCG） day, progesterone level, ovulation rate, and clinical pregnancy rate between the two groups were compared. Results  The average endometrial thickness on hCG day in the experimental group was significantly higher than that in the control group［ (8.30±1.068) mm vs (7.43±1.051)mm, P<0.01］. The proportion of type A endometrium was significantly higher than that of the control group (52.0%  vs  32.7%, P<0.05). The progesterone level in luteal phase was significantly higher than that in the control group ［(11.00±1.508)ng/mL  vs  (10.23±2.278)ng/mL, P<0.05］. The ovulation rate and the cumulative clinical pregnancy rate were significantly higher than that of the control group (88.4%  vs  79.7%, P<0.05, and 40.6%  vs  22.2%，P<0.05), respectively. Conclusions  Dingkundan can cooperate with estrogen in the treatment of thin endometrium in the clomiphene reduced ovulation cycle, improve the endometrium type, and increase the ovulation rate of clomiphene, luteal function and clinical pregnancy rate.

Key words: clomiphene, thin endometrium,  endometrium type, Dingkun Pill,  ovualtion,  pregnance