Zein extracted from defatted corn gluten meal by ethanol was hydrolyzed with an alkaline protease.The hydrolysate was refined and freeze-dried to obtain zein peptide powder containing 85.73%peptide.Using  a-tocopherol as the positive control,the antioxidant ablities of zein peptide and its separated fractions were examined by investigating their inhibiting degree to linoleic acid autooxidation.The data revealed that the zein peptide and its sepatated fractions exhibited a potent inhibiting effect on linoleic acid autooxidation,and the inhibiting effect related positively to its concentrations.The activest fraction   was fraction 2 separated by Sephadex G-15 method.The relative molecular mass distributions of the fraction 2 were mostly focused on between 200 Da and 800 Da.