Objective To analyse the curative effect of alendronate sodium in treating the postmenopausal osteoporosis patients. Methods A total of 80 patients with postmenopausal osteoporosis were randomly divided into observation group and control group, the observation group accepted a treatment with Alendronate Sodium Tablets, while the control group was given a treatment with placebo, Caltrate 600-D was added to patients in both groups for 12 months(6months as a course of treatment). Patients in two groups were observed before and after the treatment, changes of bone mineral density, bone metabolic markers, new fracture incidence and clinical adverse reaction were compared. Results After 2 courses of treatment, the comparison of bone mineral density, serum osteocalcin, C end peptide levels in the two groups had statistical significance, P <0.05; no new fractures and any obvious adverse reaction occurred in both groups. Conclusion Allen phosphoric acid sodium was good at treating the postmenopausal osteoporosis, with its obvious function of inhibiting bone resorption. It was also capable of reducing the vertebral bone loss in postmenopausal women, with fewer side effects. It might be a ideal drug in postmenopausal women for prevention and treatment of osteoporosis.