Abstract: Objective: To investigate the effect of metformin on serum advanced glycation end products (AGEs) in ovariectomized (OVX) rats. Methods: Forty female SD rats underwent bilateral ovariectomy or sham operation, three months later they were randomly assigned into four groups for metformin treatment: Sham rats, OVX rats, OVX+50 mg/kg/day rats, and OVX+100 mg/kg/day rats. Another three months later, all rats were sacrificed to evaluate the histology differences between different groups and to compare the serum AGEs differences by enzyme-linked immunosorbent assay (ELISA). Results: Compared with Sham group, bilateral ovariectomy induced impaired bone mass and increased serum AGEs; while metformin treatment significantly reversed these actions, leading to improved bone mass and decreased serum AGEs. However, there was no significant difference between OVX+50 mg/kg/day rats and OVX+100 mg/kg/day rats. Conclusion: Metformin may have a direct inhibition effect on bone loss in postmenopausal osteoporosis, and this action could be partly mediated through regulating AGEs levels in vivo.