Abstract：The general composition and amino acid composition were determined,and the enzymatic hydrolysis technology of collagen was optimized in common freshwater fish scales. The scales were found to be mainly composed of protein(more than 55%)and inorganic substances. There was rich in hydroxyproline in the composition of amino acid in the freshwater fish scales. The optimal conditions had been showed by orthogonal tests as the following:the substrate at a rate of 100 g/L,hydrolyzing at temperature of 55 ℃,and ratio of enzyme to substrate equaling to 3.0 %. In this condition,the hydrolytic collagen had small molecular weight and the central distribution.
