Abstract: In the experiment, ovalbumin was hydrolyzed by alkaline protease to obtain antioxidant peptide. Using DPPH radical scavenging activities and degree of hydrolysis as index, single factors including substrate concentration, enzymolysis time, enzyme concentration and enzymolysis temperature, were applied to research their influences on the preparation. Orthogonal experiment showed the most suitable condition of alkaline protease to hydrolyze ovalbumin was substrate concentration of 4%, enzymolysis time of 6h, alkaline protease of 5500U/g, enzymolysis temperature of 65℃ respectively. In this condition, DPPH radical scavenging rates reached 96.92%, and degree of hydrolysis was 57.14%. Enzymolysis time had the greatest influence on DPPH radical scavenging activities and substrate concentration had the greatest influence on degree of hydrolysis.