To investigate the impacts of Jiawei Erxian decoction combined with letrozole for ovulation induction of patients with polycystic ovary syndrome (PCOS) on their levels of serum anti Mullerian hormone (AMH) and sex hormones. Methods: 86 patients with PCOS diagnosed in hospital were selected and were randomly divided into two groups (43 cases in each group) by random number table method from March 2020 to August 2023. The patients in the control group were treated with letrozole for ovulation induction, while the patients in the study group were treated with Jiawei Erxian decoction combined with letrozole for ovulation induction. The ovulation induction status before and after treatment, such as the number of mature follicles, cervical mucus score and endometrial thickness during ovulation, the levels of sex hormones, such as estrogen (E2), follicle stimulating hormone (FSH), testosterone (T) and luteinizing hormone (LH), the AMH level and the adverse reactions rate of the patients in the two groups were statistically analyzed. Results: The number of mature follicles (5.3±0.6 follicles), the cervical mucus score (11.9±1.4 points), the endometrial thickness during ovulation (9.2±1.1 mm) and the pregnancy rate (74.4%) of the patients in the study group were significantly higher than those (3.8±0.5 follicles, 9.2±1.1 points, 6.5±0.9 mm and 46.5%) of the patients in the control group. The levels of the serum E2, T, LH and AMH of the patients in the two groups had decreased significantly and the FSH levels of the patients in the two groups had increased significantly, and the changes of which of the patients in the study group were significantly greater than those of the patients in the control group (all P<0.05). There was no difference in the incidence of the adverse reactions (16.3% vs. 9.3%) of the patients between the two groups (P>0.05). Conclusion: Jiawei Erxian decoction combined with letrozole for treating the patients with PCOS can significantly improve their ovulation situation and sex hormones levels, decrease their AMH level and increase their pregnancy rate after treatment.