Inonotus obliquus polysaccharide is one of the major constituents of active components in Inonotus obliquus, which has important function on antioxidant, anti-tumor etc. and is one kind of potential health ingredients. Study the progresses of Inonotus obliquus polysaccharide, including the extraction, isolation, purification, identification, bioactivity and composition, and offer the futher researchs and prospects of Inonotus obliquus polysaccharide.