Abstract: The salted egg white was used as raw material, the acid protease was used to hydrolyse salted egg white, protein recovery (PR) and degree of hydrolysis (DH) of salted egg white were analyzed, The process of enzymatic hydrolysis of the salted egg white was optimized by single factor experiments, and then the peptide molecular weight distribution of the hydrolyzate was determined. The optimal technological conditions observed by this study were as follows:the diluted salted egg white solution was adjusted to pH4.0, and was added with acid protease at the concentration of 0.3% (E/S) , and the hydrolysis reaction was conducted at 55℃ and lasts 48h. The peptide molecular weight of the hydrolyzate obtained under the optimal technological conditions mainly was smaller than 3000u, among them, peptides molecular weight of 1000³000u accounted for 49.28%, peptides molecular weight of less than 1000u accounted for 35.73%.