Abstract: Sweet potato polysaccharide is an important active ingredients of sweet potato,which mainly includes arabinose,galactomannan,pectin,and so on. It has anti-oxidation,anti-fatigue,anti-tumor,anti-inflammatory,anti-bacterial,blood sugar lowering,regulating immunity and intestinal flora effects,and is widely used in medicine,food and animal nutrition. This paper summarizes the preparation methods,biological activity,and application of sweet potato polysaccharide,which can provide some references for indepth study of the function and mechanism,develop functional foods of sweet potato polysaccharides.