The enzymatic hydrolysis of Trachurus japonicus protein by papain, neutral proteinase ,alkali proteinase and composite enzyme were studied and the neutral proteinase is shown to be the most suitable one. The optimal pH value, reaction temperature, enzyme dosage, reaction time and the ratio of muscle to water were 6.8, 60℃, 1600 IU/g, 5.0 hour and 1:2, respectively, under which the rate of enzymatic hydrolysis was 62.2%.