To investigate the association between osteoporosis and severe periodontal attachment loss in postmenopausal women. One hundred and ninety-five postmenopausal women aged 50-65 years old were included in the present study. The participant were recruited from patients in the Peking University International Hospital and through website from March, 2017 to August, 2018. Periodontal examination, filling out a structured questionnaire and bone mass density (BMD) examination were completed to each of the participants. The clinical attachment loss (CAL), oral hygiene index simplified (OHI-S), and bleeding on probing (BOP) were examined and recorded as periodontal parameters. The structured questionnaire was used to collect information of the physical activity, socioeconomic status, marital status, oral health habits, and so on. Bone mass density of the lumbar spine and left hip were scanned by using standardized dual energy X-ray absorptiometry. Based on the T-score of BMD (difference between the measured BMD and the mean value of young white women in terms of standard deviations), osteoporosis was defined as T-score≤-2.5 (according to the World Health Organization criteria). Fourteen risk factors were preliminarily screened by -square test, including age, duration of menopause, body mass index (BMI), exercise habit, economic status, marital status, level of education, habit of dental visit, tooth brushing habit, usage of interdental tools, OHI-S, BOP(+)%, osteoporosis in hip and osteoporosis in lumbar. Factors with 0.05 were selected for multivariate Logistic regression analysis. Logistic regression was used to analysis the risk factors of severe periodontal attachment loss. The mean age of 195 postmenopausal women was (57.8±4.3) years. After adjusting for ages, the economic status, habit of dental visit, OHI-S and BOP(+)%, there was an association of osteoporosis in hip and severe periodontal attachment loss in postmenopausal women [odds ratios ()=2.466, 95% confidence intervals () was 1.173-5.185, 0.017]. Postmenopausal women with osteoporosis in hip has a greater chance of presenting severe periodontal attachment loss.