The purpose of this study is to establish of predictors for bone mineral density(BMD) in Korean middle-aged women and to present basic data of an effective exercise program for the prevention and cure of osteoporosis. The subjects were 49 middle-aged women, who were divided into 22 in exercise group and 27 in non-exercise group, and then BMD of radius, lumbar and femur, body composition, VO₂max and muscle strength were measured. The results from t-test of each variable, analysis of correlation and analysis of stepwise multiple regression are the followings. 1) It was showed that BMD of femur, weight and peak torque of right extension muscle and right flexion muscle in exercise group were significantly higher than those in non-exercise group. 2) For exercise group, BMD of radius had a significant correlation with grip strength and peak torque of left extension muscle, and especially grip strength was seen as a significant predictor. BMD of lumbar had a significant correlation with peak torque of left and right extension muscle, and peak torque of left extension muscle was seen as a significant predictor of BMD of lumbar. BMD of femur had a significant correlation with weight and peak torque of right extension muscle, and weight was seen as a significant predictor of BMD of femur. 3) For non-exercise group, the only age had a significant negative correlation with BMD of radius, lumbar and femur, and was seen as a predictor of BMD. Regular exercise has positive effect not only on increase of BMD but also on increase of the amount of lean body mass, aerobic capacity and improvement of muscle strength. The exercise, in process of which continuous weight bearing can be given, is more effective, and especially in order to maintain and improve BMD of radius, lumbar and femur, which are more likely to result in a fracture of bone caused by osteoporosis, it is mare effective to carry out muscle strength which can make continuous muscle contraction for parts concerned. The result of this study, I suggest that a succeeding study on practical exercise program is need for the prevention and cure of osteoporosis through regular exercise based on the predictors of BMD.