To evaluate the efficacy of combined medication of risedronate sodium and raloxifene, a selective estrogen receptor modulator (SERM) on the postmenopausal osteoporosis (PMOP). PMOP patients underwent the combined medication of risedronate sodium and raloxifene (SERM, Treatment group), or only medication of risedronate sodium (Control group). After medication, more significant increases were observed in the bone densities of the lumber vertebra (L<inf>1-4</inf>) and the neck of left femur of patients in the treatment group. Simultaneously, the levels of estrogen and progesterone in serum decreased sharply in the treatment group. After treatment, P1NP and β-CTX levels in serum decreased significantly in two groups in comparison with the levels prior to treatment, with evident elevations in the levels of BAP and BGP; similarly, ameliorations in the treatment group were much more evident than those in the control group. In addition, significant declines were identified in the VAS scores of two groups after treatment when comparing to the scores prior to the treatment, and the decline in the treatment group was more evident than that in the control group. Combined medication of risedronate sodium and SERM (raloxifene) performs better in treatment of osteoporosis than the single use of risedronate sodium, without the deterioration of adverse effect of medication.