Abstract:〔Abstract〕 Objective To investigate the clinical effect of Kuntai capsule combined with letrozole in the treatment of infertility with polycystic ovary syndrome. Methods 60 infertility patients with polycystic ovarian syndrome treated in Wanzhou district Maternal and Child Health Hospital of Chongqing from January 2019 to June 2020 were divided into control group and observation group by random number table, with 30 cases in each group. The patients in the observation group were treated with Kuntai capsule combined with letrozole, and the patients in the control group were treated with letrozole. The levels of sex hormones before and after treatment, ovarian follicle quality, endometrial thickness, ovulation rate and pregnancy rate were compared. Results After treatment, the levels of testosterone, estradiol, follicle stimulating hormone and luteinizing hormone in the observation group were significantly lower than those in the control group (P < 0.05). The number of mature follides with just over 18mm in diameter and endometrial thickness in the observation group were better than those in the control group (P < 0.05). After 50 days of treatment, the ovulation rate and pregnancy rate in the observation group were higher than those in the control group (P < 0.05). Conclusion Kuntai capsule combined with letrozole is effective in the treatment of infertility patients with polycystic ovary syndrome. It can effectively improve the level of sex hormone and the quality of ovarian follicles, increase the thickness of endometrium and improve the pregnancy rate.