Abstract: The antioxidant activities in vitro of ethanol extract from Hericium erinaceus and its different polar fractions were studied and compared. The obtained ethanol extract from Hericium erinaceus was fractionated by different inorganic solvents orderly, including petroleum ether, ethyl acetate, n-butanol and water.The contents of total phenols and flavonoids of different polar fractions and their antioxidant activities were determined and compared. The results indicated that the ethyl acetate fraction showed the highest contents of total polyphenols and flavonoids ( 16.52 mg/g and 10.08 mg/g, respectively) . The different polar fractions showed certain antioxidant activities, especially the ethyl acetate fraction whose scavenging rate on DPPH·, ·OH and ABTS⁺· was 41.64% ( 2.5 mg/m L) , 82.84% ( 2.5 mg/m L) and 89.18% ( 0.5 mg/m L) respectively.These results demonstrated that ethyl acetate fraction had the highest antioxidant activity and can be employed as effective fractions for further investigation on antioxidants.