Abstract: In this study,the antioxidant capacity of egg white polypeptide(EWP)was studied in vitro and animal experiments,and the 1,1-diphenyl-2-picylhydrazyl(DPPH)free radical,hydroxyl free radical scavenging capacity and deoxidization capacity,as well as the superoxide dismutase(SOD)activity,glutathione(GSH)and malondialdehyde(MDA)contents in serum,liver and heart of mice were determined.The results showed that the egg white polypeptide significantly exhibited scavenging effect on DPPH radical and hydroxyl radical,which the DPPH free radical clearance rate was 69.2% and hydroxyl free radical clearance rate was 68.5% in the concentration of 5 mg/mL,and the scavenging rate was positively correlated with the concentration.Egg white polypeptide could significantly increase the SOD activity and GSH contents(P<0.05)and significantly reduce the MDA contents(P<0.05)in serum,liver and heart tissues of mice. In addition,egg white polypeptide improved antioxidant activity in a dose-dependent manner within the dosage of 150~900 mg/kg.This study provided theoretical basis and data support for the development of new bioactive peptides and the improvement of added value of agricultural products.