Abstract: Three kinds of common spice oleoresins, such as ginger, black pepper and star anise, had been selected as the study object. It was researched that the capability of clearing DPPH· and ·OH, and their capability of protective effect on soybean oil. It was showed that three spice oleoresins all had free radical elimination ability which was lower than that of traditional antioxidants such as BHT and TBHQ, and the clearance rate was enhanced gradually with increasing concentrations. In addition, these three spice oleoresins all had obvious antioxidant effect on soybean oil. Its antioxidant effect was best when the addition of oleoresin was 0.20% in the previous four days.