Abstract: Alkaline protease were used to hydrolyze pigskin collagen protein to get antioxidant peptides.And to get the one with high antioxidant activity and purity, a variety of evaluative systems in vitro had been used to research the antioxidant activity of antioxidant peptides with different molecular weights which were obtained through ultrafiltration.At the same time, ion exchange chromatography and gel permeation chromatography were used to separate and purify the enzymolysis solution.It showed that: the antioxidant activity of antioxidant peptides with5~10ku which were obtained through ultra-filtration was better compared to other molecular weights.Ion exchange chromatography and gel permeation chromatography could make a good effect on separation and purification, seven components had been separated by ion exchange chromatography, including the component P1 with the highest scavenging rate on O-2·of 46.30% and IC50 of 1.24 mg /mL when the concentration of polypeptide was0.85 mg /mL.And then, the component P1 was purified into two components by gel chromatography, in which component P1-Bwith the highest scavenging rate on O-2·of 49.43% and IC50 of 0.98 mg /mL when the concentration of polypeptide was 0.9mg /mL.