多糖是一類重要的生物大分子物質，具有抗腫瘤、抗病毒、抗氧化、免疫活性調節(jié)等生物活性。多糖的生物活性與其結構有直接關系，因而對多糖結構通過適當?shù)姆椒ㄟM行修飾是目前多糖領域研究的重要方向之一。簡要地闡述多糖的化學修飾方法（包括硫酸化、羧甲基化、乙酰化和磷酸化等）研究進展，以及修飾后對生物活性的影響，以期為新藥發(fā)現(xiàn)提供依據。

Polysaccharide is an important class of biological macromolecules. It has a variety of biological activity, such as antitumor, antivirus, anti-oxidation, immune activity regulation, and so on. The biological activity of polysaccharide has a direct relationship with its structure. Thus the structural modification of polysaccharide by an appropriate method is one of the important directions of research in the field of polysaccharides. This article systematically elaborated the structural modification methods and research progress on the polysaccharide including chemical, biological, and physical methods, as well as the impact on the biological activity.