Abstract: The technics of enzymatic hydrolysis of protein in scallop processing wastes—scallop skirts by using several endoenzymes, mixed endoenzymes and exopetidases are studied in this paper. The hydrolysis effect of the multi-step enzymatic hydrolysis using mixed endoenzymes (trypsinase ∶〖KG-*3〗substilisin=3∶〖KG-*3〗1) and Flavourzyme is the best. Through the orthogonal test, the optimum conditions for two-step enzymatic hydrolysis using Flavourzyme are determined to be as follows ∶〖KG-*3〗 enzyme added 250 U/g,enzymolysis time 5.5h,temperature 55℃,pH 6.5. The degree of hydrolysis is 682%, the concentration of free amino acids in the hydrolysate is 78.40 g/L,and that of essential amino acids is 31.57 g/L.