Abstract: Objective:To investigate the antioxidant capacity of extracellular polysaccharides(EPS)of Pleurotus djamor in vitro and its efficacy in resisting oxidative damage of liver tissue in hyperlipidemia mice.Methods:The scavenging activity of EPS on O₂^-·,DPPH radical and ·OH was determined,and its antioxidant activity in vitro was determined.The hyperlipidemia mice model was established by gavage of high-fat feed:Blank control group(NC),hyperlipidemia model group(MC),positive control group(PC),high and low dose EPS group. 10 normal mice were randomly assigned to the NC group and 10 hyperlipidemia model mice were randomly assigned to the remaining group after 14 days of intervention.The effects of EPS on the activities of glutathione peroxidase(GSH-Px),superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA)and lipid peroxide(LPO)in liver tissue of hyperlipidemia mice were measured to measure their antioxidant capacity in vivo. At the same time,the pathological sections of the liver of mice were observed to explore the repair ability of EPS to liver cells damaged by oxidative stress. Results:The saturation scavenging rates of EPS to O₂^-·,DPPH radical and·OH reached 55.05%,64.09% and 28.91%,respectively. EPS could significantly increase(P<0.05)the content of antioxidant enzymes in liver tissue of hyperlipemia mice,significantly reduce(P<0.05)lipid peroxide activity,and had good repair effect on liver oxidative stress injury.Conclusion:Exopolysaccharides of Pleurotus djamor has strong antioxidant effect in vitro,and has better antioxidant ability and oxidative damage repair ability on liver tissue of hyperlipidemia mice.