From the population study of osteoporsis 586 skeletal X-rays were examined in Fukuoka City and in rural district of Saga prefecture. There was no significant differences between two groups. The metacarpal index (MI) of 50 year old group were in average 0.521±0.065 male, 0.533±0.046 female, 70 year old 0.496±0.069 male, 0.424±0.072 female, and 80 year old 0.483±0.074 male, 0.376±0.081 female respectively. These values presented considerably lower than those of Garn's and Nordin's results esp. in female of all age groups. The MI. and cortical area declined more slowly as age increases than those of Garn's but almost same as Nordin's population group in England.