Abstract: To investigate the optimum extracting process of polysaccharides from Oudemansiella furfuracea and its antioxidant activity in vitro.Extraction process of polysaccharides from Oudemansiella furfuracea was optimised by orthogonal test. And the concentration of total sugar and reducing sugar in water extraction was determined by anthrone-sulfuric acid method and DNS method, respectively. The antioxidant properties were tested by prussian blue method, salicylic acid method and pyrogallol method, respectively.The results showed that the impact sequence of the factors on the extraction rate of polysaccharide from Oudemansiella furfuracea was as follows: solid-liquid ratio > extraction time > extraction temperature > extraction times. The optimal extraction condition was solid-liquid ratio of 1∶ 40, extraction time of 1h, extraction temperature of 80 ℃, and extracted three times, and under this conditions, the extraction rates of polysaccharide from Oudemansiella furfuracea was 8.84%. In addition, crude polysaccharides from Oudemansiella furfuracea could obviously scavenge hydroxyl radicals in a dose-dependent manner ( p < 0.05) , and at the concentration of 4 mg/m L, crude polysaccharides was observed to possess strong free radicalscavenging effects against scavenge hydroxyl radicals, with a value of 48.94% ± 12.32%. In addition, crude polysaccharides from Oudemansiella furfuracea had a certain reducing power lower and its scavenging effects on superoxide anion radical was ineffective.So crude polysaccharides from Oudemansiella furfuracea had certain antioxidant activity and could be used for polysaccharide drugs and health food.