Objective:To study the the relationship between Biomechanics agent and bone mineral density(BMD) of female osteoporosis patients with MES(muscle evaluation system),and discuss the biomechanics risk factors for osteoporosis.Methods:select female patients from osteoporosis department of our hospital,assay the femur neck BMD with DEXA(dual energy X-ray absorptiometry),then assay the body weight(BW),the fat content of total body,the muscle distribution coefficient of lower limb,the maximum muscle strength. Assay body height(BH),calculate body mass index(BMI).Among the above objects,select the ones whose T-score of femur neck BMD under -2SD(standard difference) as osteoporosis patients.Analyse the relationship between the BW,BMI,the fat content of total body,the muscle distribution coefficient of lower limb,the maximum muscle strength and the BMD with Excel software.Results:From maximum to minimum,the affecting factors of BMD is BW,the maximum muscle strength, the muscle distribution coefficient of lower limb,BMI,the fat content of total body. The relationship between the fat content of total body and BMD has no statistics significance.Conclusion:BW,the maximum muscle strength,the muscle distribution coefficient of lower limb,and BMI are factors that affect BMD.Muscle is the main factor of the body composition that affects BMD,it affects BMD mainly through the dynamic loading(muscle strength), then the static loading(muscle weight). Objective: To study the the relationship between Biomechanics agent and bone mineral density (BMD) of female osteoporosis patients with MES (muscle evaluation system), and discuss the biomechanics risk factors for osteoporosis. Methods: select female patients from osteoporosis department of our hospital, assay the femur neck BMD with DEXA (dual energy X-ray absorptiometry), then assay the body weight (BW), the fat content of total body, the muscle distribution coefficient of lower limb, the maximum muscle strength. ), calculate body mass index (BMI). Among the above objects, select the ones whose T-score of femur neck BMD under -2SD (standard difference) as osteoporosis patients. Analyse the relationship between the BW, BMI, the fat content of total body, the muscle distribution coefficient of lower limb, the maximum muscle strength and the BMD with Excel software. Results: From maximum to minimum, the affecting factors of BMD is BW, the maximum muscle strength, the muscle distribution coeffi cient of lower limb, BMI, the fat content of total body. The relationship between the fat content of total body and BMD has no statistics significance. Confluence: BW, the maximum muscle strength, the muscle distribution coefficient of lower limb, and BMI are factors that affect BMD. Muscle is the main factor of the body composition that affects BMD, it affects BMD mainly through the dynamic loading (muscle strength), then the static loading (muscle weight).