The purpose of this study was to develop the educational program based on the self-efficacy theory of Bandura(1986) and to identify the effect of the program among women. For this purpose a non-equivalent control group, and a pretest- posttest design was used between the experimental and the control group. The subjects in this study were female and were over the age 40, 37 in the experimental group and 46 in the control group. In this study, the educational program was developed to increase the level of osteoporosis self efficacy and to prevent osteoporosis. The program consisted of watching, videotapes, telephone contact, lectures, and small group discussions. This study was conducted to determine whether the 6 month educational program would increase osteoporosis self- efficacy, thus modifying life styles related to osteoporosis increas BMD. The instruments utilized in this study were the Lifestyle Questionnaire, and the Osteoporosis Self-Efficacy Scale. Also, bone marrow density (BMD) on the left wrist was measured by DTX-200. The findings are as follows: 1. A significant decrease in BMD was observed in the control group. By contrast, no significant change in BMD was observed in the experimental group. 2. The Osteoporosis Self-Efficacy was not significantly changed in both the experimental and control groups. 3. In the experimental group, the number of exercise participants and their exercise times were significantly increased. Also the amount of caffeine intake was significantly decreased.