OBJECTIVE:To study the effects of metformin (MF)on serum sex hormone and leptin contents in ovariectormized female rats. METHODS: 40 SD rats were randomly divided into four groups: control group(normal saline 5 mL? kg-1?d-1,NS group),OVX group(normal saline 5 mL?kg-1?d-1),OVX+low and high dosage MF group(135,270 mg? kg-1?d-1,MFlow and MFhigh group),all group were ig drugs for 30 days on end.The serum sex hormone indexes including E2,P,LH,LSH and leptin content were measured with RIA. RESULTS:Compared with NS group,the serum E2 and P content were significantly lower(P0.05). CONCLUSIONS: MF can significantly improve sex hormone secretion and lower serum content of LEP in OVX rats.