Objective To study the effect of dehydroepiandrosterone sulfate (DHEAS) treatment of osteo porosis in men with T BMD ≥2.5SD. Methods Eighty-six patients were randomly divided into two gr oups: treatment group (n=44) and control group (n=42). DHEAS (100?mg q.d.) was given to the treatment group for 6 months. Bone mineral density, (BMD), biochemical markers of bone absorption and formation and other serum biochemical markers were measured before and after DHEAS treatment. Drug side effects were also evaluated. Results After oral administration of DHEAS (100?mg q.d.) for 6 months, the serum concen trations of DHEAS and IGF-Ⅰ in the treatment group were 93.75%±16.1% and 1 7.71%±4.2% higher respectively than those in the control group ( P <0.01) . The BMD of L2, L3, L4, L2-4 and Neck sections increased in the treatment group by 2.65%±0.65%, 2.70%±0.48%, 3.10%±0.41%, 2.82%±0.37% and 2.32%±0 .31%, respectively, as compared with that the control group ( P <0.05 or 0. 01). No significant changes were observed in serum FT, E2 and PSA concentrati ons in the treatment group as compared with the control group. Conclusion The treatment of osteoporosis in men with DHEAS is safe and effective.