The contents of the nutritional component in scallop brim were analyzed and hydrolyzed by the neutral proteases produced by the strains of Bacillus subtilis ASI.398. The content of protein in scallop brim was about 67.6% in dry weight. Then the four factors influencing the degree of hydrolysis were investigated and the optimal conditions of hydrolyzing proteins were obtained. The temperature of hydrolysis was 50℃, concentrations of neutral proteases and base material were 0.5%(250 U·ml^-1) and 6% respectively, hydrolysis time was 3 h.