Objective To investigate the impact of bilateral ovariectomy on bone mineral density, body composition and sex hormones levels in peri-menopausal women. Methods Thirty-three peri-menopausal women undergoing bilateral ovariectomy in Department of Obstetrics and Gynecology, The Sixth People's Hospital, Shanghai Jiaotong University from January 1st to December 31st 2009 were selected (ovariectomy group), and another 35 women of natual menopause visiting climacteric clinic during the same period were served as control group. Bone mineral density, fat mass, lean mass and sex hormone levels were measured by dual-energy X-ray absorptiometry and chemiluminescence method, respectively 6 and 12 months after menopause. Results Six and twelve months after menopause, there was no significant difference in bone mineral density, fat mass and lean mass between two groups (P>0.05). The estrodiol (E2) level in ovariectomy group was significantly lower than that in control group six months after menopause [（14.79±22.17）U/L vs （32.74±31.02 U/L）]（P<0.05）, and there were significant differences in E2 levels and follicle stimulating hormone (FSH) levels between two groups 12 months after menopause [E2：（8.09±4.38）U/L vs （25.92±3.53）U/L；FSH：（64.88±18.39）U/L vs （40.69±31.63）U/L]（P<0.05）. Conclusion Bilateral ovariectomy in peri-menopausal women may lead to significant changes of E2 and FSH levels within 12 months, while the decreased E2 level does not have significant impacts on bone mineral density, fat mass and lean mass.