Color polymorphism is relatively common in marine mollusks. Shell color affects the visual perception of products which, consequently, influences consumer preference and product value. To increase the value of the Pacific oyster (), five shell color strains (black, purple, orange, golden, and white) of have been developed through successive, selective breedings. The aim of this study was to evaluate the difference in the chemical composition and nutritional value of different organs of five shell-color strains and one control population. In this study, five biochemical compositions in adductor muscle, mantle, gill, and gonad-visceral mass were detected, including moisture, total protein, total fat, glycogen, and ash. Results indicate that the purple-shell strain showed a significantly higher fat content in the adductor muscle than that of the orange-shell strain (<0.05). The golden-shell strain showed significantly higher glycogen than in the black-shell, orange-shell, and control population, while the white-shell strain had significantly larger ash content in the mantle compared to the control population (<0.05). In addition, the orange-shell, purple-shell and white-shell color strains showed significantly lower glycogen in the gill than in the control population (<0.05), whereas there was no significant difference in the contents of five biochemical compositions in gonad-visceral mass between the control population and five shell-color strains. The nutritional composition appeared significantly different among the four organs. These results indicate that nutritive content significantly changed in the process of selective breeding, providing useful information for developing shell-color strains in future.