With increase of aged people, osteoporosis and its related problems were also increased. The fracture of the proximal femur cause more severe problems than other osteoporotic fractures. There was some controversies about direct cause of hip fracture. We evaluated 49 osteoporotic fractures of the proximal femur in women above 50 years of age between March 1991 and Febuary 1992. The bone density of fracture group and 124 healthy control group was measured by Dual Energy X-ray absorptiometry. The result was compared using age matched paired T test. The results were as follow 1. The femoral neck fractures were 19 cases and trochanteric fractures were 30 cases. Mean age was 65 years in neck fracture group and 79 years in trochanteric fracture. 2. In control group, the bone density was measured on both side of the proximal femur and it showed statistically no difference between both sides in same person. 3. The bone densities of spine, femoral neck, Ward triangle and trochanter area were significantly reduced in proximal femoral fracture group comparing with those of control group. 4. The trochanteric fracture group was more older and thinner than the femoral neck fracture group, but there was no statistical difference in bone density between two groups. 5. The bone density of third lumber spine in trochanteric fracture group showed significantly reduced density than that of control group (p<0.001) but the bone density of third lumbar spine in femoral neck fracture group showed no difference with that of control group (p=0.648). 6. The fracture threshold of femoral neck fracture was 0.75gm/cm², and that of trochanteric fracture was 0.63gm/cm2. The osteoporosis is important cause of eldely hip fracture. The trochanteric fracture occurs in diffuse osteoporotic patient while femoral neck fracture may occurs in localized osteoprosis in proximal femur.