Quantification of bone mineral density (BMD) is being used as the main method to diagnose osteoporosis. Dual-energy X-ray absorptiometry (DXA) is the most common tools for measuring BMD. Compared to DXA, quantitative computed tomography (QCT) can determine in three dimensions the true volumetric BMD (vBMD) at any skeletal site. In addition to the spine, the hip is an important site for axial BMD measurement. This study examines lumbar spine and hip BMD of Chinese adults by QCT. Age related changes in bone mass derived by QCT measurements were determined. The osteoporosis QCT detection rates at the spine and hip are assessed in both female and male, and agreement of skeletal status category between the spine and hip in older adults is also assessed.