Abstract： Objective： To observe the clinical effect of modified Ziyin Buyang Tiaojing Decoction on infertility caused by polycystic ovary syndrome (PCOS) of kidney deficiency type. Methods ： A total of 88 patients with infertility caused by PCOS of kidney deficiency type were selected and divided into the control group and the observation group by random number table method， with 44 cases in each group. Both groups were given life guidance and adjustment of dietary structure； they were advised to engage in aerobic exercise appropriately，maintain a good mood，avoid staying up late，and control body mass. The control group was treated with Clomiphene Citrate Tablets，while the observation group was treated with modified Ziyin Buyang Tiaojing Decoction on the basis of the control group. Three menstrual cycles constitute one course of treatment，with both groups receiving two courses of treatment. Clinical effects in the two groups were evaluated. The changes in traditional Chinese medicine (TCM) syndrome scores，sex hormone indicators [follicle stimulating hormone (FSH)， luteinizing hormone (LH)， estradiol (E2)， and testosterone (T)]， uterine volume， ovarian volume， and follicle number before and after treatment were compared between the two groups. After three months of follow-up， the pregnancy rates in the two groups were counted. Results：The total effective rate was 93.18% in the observation group，which was higher than that of 77.27% in the control group (P＜0.05). After treatment， TCM syndrome scores in the two groups were decreased when compared with those before treatment (P＜0.05)， and each TCM syndrome score in the observation group was lower than that in the control group (P＜0.05). After treatment， FSH and E2 in the two groups were increased when compared with those before treatment， and FSH and E2 in the observation group were higher than those in the control group (P＜0.05)； LH and T in the two groups were decreased， and LH and T in the observation group were lower than those in the control group (P＜0.05). After treatment，uterine volume in the two groups were improved when compared with those before treatment，and uterine volume in the observation group was larger than that in the control group (P＜0.05)； ovarian volume and number of follicles in the two groups were reduced when compared with those before treatment， and ovarian volume and number of follicles in the observation group were smaller than those in the control group (P＜0.05). During the three-month follow-up， the pregnancy rate was 75.00% in the observation group，which was higher than that of 52.27% in the control group (P＜0.05). Conclusion：For patients with infertility caused by PCOS of kidney deficiency type，modified Ziyin Buyang Tiaojing Decoction can effectively improve their clinical manifestations，regulate hormone levels，improve uterine and ovarian volume，and increase pregnancy rates.