The purpose of this study was to identify the risk factors of osteoporosis. The data were collected from women who visited Physical Examination Center of a university hospital located in Taejon during the period of September 1997-August 1998. The sample was divided into two groups(the osteoporosis group of 44 cases and the control group of 66 cases). The results were summarized as follows ; 1. Sociodemographic characteristics(education and family income) and BMI showed no significant difference between the osteoporosis group and the control group. 2. There was no significant difference in coffee, unbalanced diet, diet method and meal habit between the osteoporosis group and the control group. 3. The osteoporosis group reported more incidence of operative menopause due to hysterectomy and oophorectomy, but this was not statistically significant. There was no significant difference in use of oral pill use, past disease and family history of fracture between the osteoporosis group and the control group, but the odds ratio(OR 3.11, 95% CI : 1.30-7.41) of present illness was statistically significant in the osteoporosis group. 4. There was no significant difference in the reproductive history including number of delivery and abortion and feeding method between the osteoporosis group and the control group. 5. The osteoporosis group showed significant results of lower menopausal age, shorter duration of menstruation and longer duration after menopause compared to the control group. 6. The osteoporosis group reported significantly lower level of physical activity in such variables as work activity and walking time. 7. A logistic analysis showed that shorter period of menstruation, lower level of physical activity, non-alcohol drinking group, and presence of disease were related to the possibility of occurring of osteoporosis.