Abstract: Polysaccharides are a class of macromolecules widely found in plants, animals and microorganisms, with various bioactive activities, including immunomodulatory, antitumor, hypoglycemic, antiviral, and antioxidant etc. Among a number of biological activities, the antitumor effect is relatively clear. This article focuses on the research progress on the structure-antitumor activity relationship and its mechanism of polysaccharides at home and abroad in recent years.

Key words: polysaccharide, antitumor, structure-activity relationship, mechanism