As the human life becomes longer, Involutional osteoporosis is becoming increaseingly recognized as a major health care problem. The incidence of osteoporotic fracture is rising in all countries and, if the current trends continue, then the prevalence of hip fractures will double over the next 20 years. Awareness of osteoporosis has coincided with the realization that osteoporosis can be prevented in part, not only with hormone replacement,but also with other interventions which prevent or delay the rate of bone loss. Much attention has focused on prevention and the use of physical and biochemical techniques which can assess the risk of osteoporotic fracture. Techniques for measuring bone mineral density have been widely accepted for the diagnosis and management of osteoporosis. These techniques are clinically feasible, and their fracture prediction capability has been proven in numerous studies. However, it has been demonstrated that bone strength and fracture risk are affected not only by the density of bone but also by other skeletal features including bone composition and microarchitecture. Theoretically, QUS(Quantitative Ultrasound) may reflect not only bone mass but also bone structure. In this study, we have examined the relationship between SI(Stiffness Index), SOS(The speed of sound), BUA(Broadband ultrasound attenuation) measured in the os calcis by QUS and BMD(Bone mineral density) measured in lumbar spine and femur neck by DEXA(Dual energy X-ray absorptiometry) in 18 marked osteoporotic patient. All QUS parameters poorly correlated with BMD measured in lumbar spine(SI; C.C.=0.2795, SOS; C.C.=0.0355, BUA; C.C. 0.3110) and in femur neck(SI; C.C.=0.2239, SOS; C.C.=0.0742, BUA; C.C. 0.3130) in contrast to good correlation in normal and mild osteoporotic women. Considering the report that at 2 standard deviations below the normal mean QUS has the maximum accuracy, these findings may imply tbat QUS reflect the disruption of the intrinsic trabecular architecture, the integrity of which