Single-factor experiments and response surface analysis were adopted to study the effect of ,pH value and enzymolysis temperature on preparation of antioxidant peptide,with the DPPH radical scavenging rate as the response value.According to the above results,the optimum enzymatic hydrolysis conditions for preparation of antioxidant peptides from Walnut protein using alkaline protease enzyme was obtained as follows;2.6%,pH 9,enzymolysis temperature 49℃,[S]2%,enzymolysis time 2h.Under these conditions,the scavenging rate of DPPH radical is up to 69.85%.