Tilapia skin protein was hydrolyzed by Alcalase2.4L,Protamex,Papain,PTN6.0S,Neutrase enzymes.The hydrolysis reactions catalyzed by these enzymes were studied.Results revealed that the protein utilization,peptide yield and the degree of hydrolysis of Tilapia skin protein by PTN6.0S and Alcalase2.4L were higher than those by the other enzymes.Among the achieved hydrolysates,the hydrolysate achieved with Alcalase2.4L∶ PTN6.0S(1∶ 2) had the best result,the protein utilization,the degree of hydrolysis and peptide yield were respectively 96.37%,13.24% and 83.13%.After the ultrafiltration treatment,the ratio of the molecular weight less than 3000 u reached 97.73%,the total amino acid content increased from 97234.79mg/100g to 84076.12mg/100g.