In order to obtain polypeptides from pig bone collagen as much as possible, the enzymolysis process of bone collagen was optimized. On the basis of one-factor and double-factor interaction tests, according to Box-Behnken central composition design principle, the method of response surface analysis with 3 factors （substrate concentration, Protamex-compound protease concentration and hydrolysis time） and 3 levels combined with Minitab14-statistical data analysis software was adopted to built a quadratic regression equation with pig bone polypep...
