Bovine hide and pig skin gelatins were prepared and their molecular weight profiles were examined by SDS-PAGE. The major molecular weights of bovine hide gelatin were 220 kDa, 140kDa, and 130kDa and the weights of pigskin gelatin were 210 kDa, 135kDa and 120kDa. Also , as a typical parameter of rheological property of the gelatin , viscosities of gelatin were measured under various conditions. Gelatin hydrolysates were prepared using typical commerical proteases and their angiotensin converting enzyme inhibitory activities were examined.