For determination of reliability and clinical applicability of spinal mineral content assessed by quantitativeCT, the basic experiment was undertaken to assure the correlation of CT numbers of calibration material withinphantom and human vertebral specimen. And the analytical study of mineral contents assessed by whole body CT in 208 normal persons was performed at Pusan Natinal University Hospital for these last two years. The resultsobtained were summarized as follows: 1. The concentration of solution of dipotassium hydrogen phosphate had a highcorrelation with CT number with correlatin coefficient of 0.99. 2. in experimental study, the method fordetermining the mid-vertebral line in lateral scout view showed the precision of 1.4%(coefficient of variation).3. Short term precision test for mineral content of spine specimens showed 1.9%(coefficient of variation) and longterm precision test showed 2.4%(coefficient of variation). 4. Mean mineral content of lumber spines in normal malewas 139.0±35.70mg K2,HPO4/cm³, and the highest value was 167.3±22.96mg K2 HPO4/cm³ in the age range of 20–29years. With increasing age, there was a gradual loss of mineral. so that by age 70 the mineral content was reducedto 85.2±19.95mg K2 HPO4/cm³. 5. Mean minearal content of lumbar spines in normal female was 128.7±41.87mg k2HPO4/cm³. the highest value was 169.5±20.46mg/ K2 HPO4.cm3 in second decade. There was gradual decrease inmineral content to 62.2±25.45mg K2 HPO4/cm³ by 70 years of age. 6. From 40's of age the average mineal content ofspine was decreased by 70's, the mineral content in normal women was reduced by 62%, and that in normal men by 47%. 7. After 40's in women, the mineral content of spine was markedly reduced, and the level of mineral contentin women was lower than in men.