Abstract: Objective：To discover the influencing factors of the bone mineral density（BMD） of premenopausal women and provide the scientific basis for osteoporosis. Method：Dual-energy x-ray absorptiometry is used to test 149 healthy premenopausal women for their bone mineral density and body composition combined with the questionnaire survey of their nutriture，life styles, physical activity level, medicine and disease history, menstruation and fertility situation. The influencing factors are screened through correlation analysis, one-way variance analysis and multiple regression analysis. Results： Bean products，physical activity level，activity between 18 to 30，weight，lean body mass，fat mass and BMI have positive relation with BMD. The physical activity level，activity between 18 to 30 and the lean body mass are entered into the multivariate regression equation. Conclusion：The physical activity level，activity between 18 to 30 and the lean body mass are the most sensitive factors.