This study was conducted to get a knowledge on food components of cuttle bone (CB) as a food resource. The yields and ash contents of CB were about on whole cuttle fish and about on dry basis, respectively, The contents of heavy metal might not invoke health risk in using food resource, The major mineral of CB was calcium as about in content. The yields, proximate compositions, heavy metal and mineral contents were not significantly different between domestic and imported CB. Judging from X-ray diffraction pattern, most of calcium in CB was present as a form of calcium carbonate (CC), and scanning electron micrograph showed irregular form. Buffering capacity of CB showed strongly at pH 7, and its pattern was the same as shown in that of CC, And CB solution showed a very high degree in turbidity comparing to that of CC solution. The solubility of CB was superior to that of CC, but inferior to those of calcium powders on the market, It was concluded from above results that CB could be effectively utilized as a calcium source.