The aim of this Phase III, randomized, double-blind, placebo-controlled, parallel-group study is to evaluate the efficacy and safety of denosumab (DMAb) in Chinese postmenopausal women with osteoporosis at increased risk of fracture. The study design consists of two phases: Screening and 12-month Double-Blind treatment phase. Following the Screening phase, all eligible subjects will be randomized to receive Double-Blind DMAb (60 mg) or Placebo study medication in a 3:1 ratio. DMAb 60 mg and placebo will be administered as a single subcutaneous (SC) injection at the beginning of the Double-Blind phase and at 6 months following the initial dose. All subjects will receive daily supplementation of oral elemental calcium (at least 600 mg) and vitamin D (at least 400 International Units [IU]). The primary objective is to determine the effects of DMAb compared to placebo with respect to mean percent change in BMD at the lumbar spine, as measured by dual-energy x-ray absorptiometry (DXA), from Baseline to Month 12. Secondary objectives include the evaluation between the DMAb and placebo treatment groups: change in BMD: at the lumbar spine (Month 6), total hip (Months 6 and 12), femoral neck (Months 6 and 12) and trochanter (Months 6 and 12); and serum biomarkers of bone formation and resorption (Months 6 and 12). Clinical safety of denosumab will also be assessed in this population.