The changes in collagen contents of chicken gizzard and breast meat during boiling water and pressure cooking were investigated. The loss of collagen in both tissues increased as the cooking time or temperature increased. The percent of collagen in acid-and salt-soluble forms in gizzard was lower than that of the breast meat. The acid-and saltsoluble collagen from water cooked gizzard were lower than those of the pressure cooked gizzard. Cooking gizzard in boiling water containing 0.5% acetic acid or papain significantly (p