Abstract:Perilla frutescens polysaccharides（PFP）were obtained by water extraction and alcohol precipitation.Then they were isolated and purified by DEAE-52 cellulose chromatography，and a total of four polysaccharide components PFP-1，PFP-2，PFP-3 and PFP-4 were obtained.PFP-1 was a neutral oligosaccharide，but the total sugar content was lower.PFP-2 had a molecular weight of 4.7 kDa while the peak molecular weight was 2.2 kDa，and the main monosaccharide was galacturonic acid.PFP-3 was mainly composed of two molecular weight segments of polysaccharides，with the main peak molecular weights of 5.2 kDa and 40.0 kDa，and was a heteropolysaccharide，containing many kinds of monosaccharides，mainly galacturonic acid and galactose.PFP-4 had a low molecular weight，and its main monosaccharide components were galactose and arabinose.In vitro antioxidant activity test showed that PFP had strong DPPH radical scavenging activity，ABTS+radical scavenging activity and Fe3+reduction ability，and had good antioxidant activities.The antioxidant activities of components PFP-3 and PFP-4 were close to those of PFP，and they were the key components to play its antioxidant role.