Abstract: OBJECTIVE To investigate the clinical efficacy and mechanism of acupuncture and traditional Chinese medicine combined with letrozole in the treatment of infertility with polycystic ovary syndrome (PCOS) ovulatory disorder. METHODS 50 patients with PCOS ovulatory disorder were randomly divided into two groups: treatment group (acupuncture and medicine combined with letrozole) and control group (letrozole group)， 25 patients in each group were treated for three months. The changes of TCM symptom score， the ratio of follicle stimulating hormone (FSH)， luteinizing hormone (LH)， testosterone (T)， LH/FSH and the changes of endometrial thickness were observed before and after treatment， and the number of ovulation cycles and ovulation rate were counted. The expression level of Lethal-7 (Let-7)， rogen receptor (AR)， cyclooxygenase (COX-2) and dimodulation protein (Areg) were detected by qPCR before and after treatment. RESULTS Compared with the group before treatment， the scores of TCM symptoms and the levels of LH， LH/FSH， T decreased， the thickness of endometrium growed， the expression of Let-7 increased and the expression of AR， COX-2， Areg decreased after treatment (P<0.01). Compared with the control group， the score of TCM symptom was lower， the number of ovulation cycle was larger， the expression of AR was lower(P<0.01)， and the levels of LH， LH/FSH， T was lower(P<0.05， P<0.01). The endometrial thickness was better(P<0.05)， and the pregnancy rate (60%) was higher than that of the control group (32%) (P<0.05). CONCLUSION Acupuncture and traditional Chinese medicine combined with letrozole can regulate the level of sex hormones， improve the endometrium， increase the number of ovulation cycles and increase the pregnancy rate in infertile women with PCOS. The mechanism may be related to the regulation of androgen receptor pathway.