Objective To investigate the body components and bone mineral density(BMD) in healthy young men, providing the basis for the prevention, diagnosis and treatment of osteoporosis. Methods Body components, whole bone density, and bone density of arms and lumbar vertebrae in 155 healthy young men aged 18.0-23.9 were measured by dual energy X-ray absorptiometry. Results BMD of arms increased with age, while the BMC and BMD of other parts and the whole bone density had no significant age specific differences (P0.05). BMD of all parts except lumbar vertebrae increased with increasing BMI(P0.01). The correlation coefficient(r) of L_(2-4) and lean body mass was 18.5-24.9, lean body mass increased with increasing BMI, and when BMI increased to 25 and above, the lean body mass no longer increased. Conclusions Lean body mass may be the main factor influencing the bone density.