Abstract: Objective: To observe the efficacy and tolerability of a daily alendronate in improving bone mineral density (BMD) and bone turnover markers in Chinese osteoporotic women. Subjects and methods:274 Chinese osteoporotic women, 49-82 years old with more than 3 years of menopause period were included. 10mg Alendronate and 500mg calcium were prescribed daily. The bone mineral density (BMD, by Lunar DPX-L，Norland XR-36 or Hologic QDR-2000), urine NTX/Cr(by Elisa, kit of Osteomark, USA), serum calcium, phosphate and alkaline phosphatase levels(by autonomic analysis) were measured to evaluate the efficacy. The side effects, liver and kidney function (by autonomic analysis) were observed to assess the tolerability. Results: BMD at Lumbar 2-4, Neck, Wards and Trochanter sites were increased significantly by 4.1%, 2.5%, 3.3% and 2.4% respectively（P<0.001）. Urine NTX/Cr and alkaline phosphatase levels decreased by 31.6% and 26.7%（P<0.001 vs baseline）. It indicated that Alendronate effectively inhibited bone turnover. Body height of patients had no change. Except one case with foot phalange fracture caused by a trauma, no new fracture occurred during treatment. Blood and urine routine test, liver and kidney function were all in normal ranges. Mild upper gastrointestinal side effects were found in 4.4% cases possibly related to Alendronate. Conclusion: Alendronate was effective and well tolerated in Chinese postmenopausal osteoporotic women.