Abstract: In order to realize the high value utilization of Katsuwonus pelamis,the enzymatic hydrolysis process of Katsuwonus pelamis was optimized,and the amino Acid composition characteristics of Katsuwonus pelamis were analyzed. Using the degree of hydrolysis as an indicator,on the basis of single factor experiments,the amount of enzyme content,the material-liquid ratio,the hydrolysis temperature,the hydrolysis pH and the hydrolysis time were optimized by Box-Behnken center combination design and response surface methodology. The results showed that the optimal enzymatic hydrolysis conditions was enzyme addition 5000 U/g,material-liquid ratio 1:4 (V/V),hydrolysis temperature 49.17 ℃,hydrolysis pH6.6,and hydrolysis time 5 hours. The theoretical maximum value of the hydrolysis degree was 23.74%,and the actual value was 23.15%±0.22%,which was in good agreement with the response surface prediction value. The contents of the essential amino acids and the umami peptide amino acid was plentiful and basically the same as the essential amino acid pattern recommended by FAO/WHO. Therefore,Katsuwonus pelamis peptide had good nutrition and delicious flavor. It would be a high-quality marine protein peptide resource with great development potential.