DPPH自由基的EC50值为0.217g/(100mL)。Protease screening was employed to prepare rice anti-oxidation peptide with enzymolysis method. Scavenging rate of hydrolysate to the DPPH radical was used as an index with rice protein as the raw material. Neutral protease was screened out from the following seven kinds of protease. These kinds of protease were flavor protease, neutral protease, trypsin, complex protease, alkaline protease, papain and pepsin respectively. The optimum hydrolysis conditions obtained from the experiments were as the following: concentration of substrate was 1.0 g/(100mL), ratios of enzyme-substrate was 8%, pH value 6.0, 60℃ and 30min of reaction time. After being diluted 15times, scavenging rate of hydrolysate liquid to the DPPH radical 89.45% could be obtained and EC50 value of hydrolysate scavenging DPPH radical was 0.217 g/(100mL). 