To prepare for the problems associsted with a rapidly aging society, a checkup for the bone mineral density has been performed in many cities and villages in Japan. However, there are varying methods for measuring bone mineral density, and the usefulnes of quantitative Ultrasound imaging has not been established. The relationship between bone mineral density and life style in 627 women in 5 cities was investigated using quantitative ultasound imaging to measure bone mineral density. The results can be summarized as follows: 1. The results from quantitative ultrasound imaging can be applied to the established DXA method because there was a correlation among dual energy X-ray absorptiometry. single energy X-ray absorptiometry and quantitative ultrasound imaging. 2. The stiffness index by quantitative ultrasound imaging was highly correlated with age and decreased proportinally with an increase in age. 3. We suggest that the measurement of bone mineral desity by quantitative ultrasound imaging for women at the age of 55 and 60 years in addition to those of 40 and 50 years is necessary. 4. We speculate that exercise and celcinm intake during youth have some effects on bone mineral density of woman after the prime of life.