With isolated soybean protein as raw material,three commercial proteases(Alcalase,Neutrase,Pepsin) were used to prepare soybean peptides with antioxidant ability.The antioxidant capacities(AOC) of enzymatic hydrolysates were evaluated by ORAC(oxyen radical absorbance capacity).The results showed that,in the appropriate enzymatic condition,the ORAC value of the hydrolysate zymolysised by Alcalase,which was1 900.48 μmol Trolox equivalent/ g Peptide,1 711.91 mg Glutathione equivalent /g Peptide,was the highest,that by Neutrase took the second place,and that of Pepsin was the lowest.At the same time,the significant correlation between ORAC value of soybean peptide and its DPPH radical scavenging capacity was found.