Abstract: Yam(Dioscorea opposita Thunb.)polysaccharide,the major nutrient and bioactive substances in the yam,has various physiological functions including anti-oxidation,maintenance of intestinal homeostasis,immunomodulation,hypoglycemia and liver protection. Yam polysaccharide is easy to be metabolized and has no toxic side effects. Under certain conditions,the polysaccharides can also exhibit better emulsification and rheological properties,showing broad application prospects. In this paper,the structure,function and physicochemical properties of yam polysaccharides are introduced. This review enumerates various yam polysaccharides’ the molecular weight,monosaccharide composition,glycosidic bond type,ect. It also introduces the mechanism of biological activity and the influence factors of physical and chemical properties,meanwhile the product development and further investigation directions of yam polysaccharides are prospected. This paper might provide some references for the further research and application of yam polysaccharides in the future.