The structural characterization and antioxidant activity of four Auricularia polysaccharides (A.cornea ACP)、A.auricula(AAP)、A.polytricha (APP) and M.fungus(MFP)) were studied in this paper. The results shown: polysaccharides of four Auricularia were mainly composed of mannose and galactose, all polysaccharides contained uronic acid and pyran ring structure with spectroscopy and NMR analysis. There was a significant difference in the total antioxidant capacity and APP was significantly higher than the other polysaccharides. The ability of APP to scavenge DPPH radicals and hydroxyl radicals was significantly higher than that of other polysaccharides, respectively. The molecular weight was significantly positively correlated with DPPH radicals, superoxide anion radicals and hydroxyl radicals. Total antioxidant capacity was significantly negatively correlated with fucose and galactose. The result indicated that fucose and galactose jointly determine total antioxidant capacity. The polysaccharide from four Auricularia had good oxidation resistance and could be used as natural antioxidants.