Abstract: As one of the main active ingredient of Pleurotus ostreatus,Pleurotus ostreatus polysaccharides were acclaimed in food research field owing to its antioxidation,antitumor and immunomodulatory functions. This paper reviewed the research progress of the extraction,purification,structure and biological activity of Pleurotus ostreatus polysaccharides at home and abroad in the last 20 years,and then proposed the problems encountered during the investigations of Pleurotus ostreatus polysaccharides,which would provide a useful guidance for the future studies.