, enzymatic hydrolysis is employed to extract pro- teins and produce peptides(Morimura et al., 2002), which forms an effective way to recover proteins from the byproduct of animal processing industries. Unlike acidic or alkaline hydrolysis, enzy matic proteolysis is mild and controllable, which helps to improve the quality and functional properties of protein(Kristinsson& Rasco 2000a). An enzymatic process using specific protease has been developed to produce flavorants from seafood byproduct(Baek Cadwallader, 1995). However, due to the stable protein structure of bone, the enzymatic hydrolysis generally has lower DH, which is a means to determine the properties of protein hydrolysates As a result, it is still difficult to extract proteins from the bone com pletely by enzymatic hydrolysis