To observe clinical effect of Chaihu Longgu Muli Decoction in the treatment of amenorrhea induced by antipsychotic drugs and to discuss the treatment mechanism. Methods:Sixty female patients with amenorrhea due to antipsychotic drugs who received treatment from September 2014 to April 2016 in psychiatric outpatient and inpatient department were selected and randomly divided into the observation group and the control group, with 30 cases in each group. Patients in the two groups all orally took aripiprazole, an antipsychotic drug and patients in the control group additionally were treated with mesylate bromocriptine tablets, while patients in the observation group additonally received Chaihu Longgu muli Decoction. The menstrual cycle and menstruation condition of the two groups were observed and recorded and the recurrence of amenorrhea was observed during the six months follow-up. Blood samples were taken at 8-9a.m. by enzyme linked immunosorbent assay (ELISA) and automatic biochemical analyzer (Hitachi 7180) was applied for tests on serum levels of prolactin (PRL), luteinizing hormone (LH) and estrogen (E2) and ultrasound B test were used to detect endometrial thickness changes before and after the treatment. The short-term and long-term curative effects were evaluated. Results:After the treatment, PRL of the two groups decreased to norma (102-496 mIU/L), (P<0.01) and LH and E2 significantly improved (P<0.01). The differences in PRL, LH and E2 in the two groups were statistically significant (P<0.01). The endometrial thickness in the observation group was significantly lower than that in the control group after the treatment (t＝4.14, P=0.000＜0.05). The curative rate of the observation group after the treatment was 55.17% and the total effective rate was 82.76%, while the curative rate of the control group was 35.17% and the total effective rate was 71.43%. The difference between the two groups showed statistically significant (P<0.05). The recurrence rate of the observation group was only 6.25%, while that of the control reached 20%. The recurrence rate of the observation group was significantly lower than that of the control group (P<0.05). Conclusion:Chaihu Longgu Muli Decoction may improve the secretion level of E2 and LH, by reducing the level of PRL in these patients and improve the amenorrhea caused by antipsychotic drug without severe adverse reactions.