Abstract: Biologically active polysaccharide has many kinds of physiological activities and health care functions.The strength of antioxidant capacity of plant polysaccharides is related with its sources,properties and structures.With the increasing demand of polysaccharide market,some test methods of antioxidant activities which are quick,sensitive and practical are particularly important.At present the tests are mainly used in the following three platforms: in vitro chemical simulation,cellular level and individual level.This paper briefly reviews the methods and principles of detecting antioxidant activities of plant polysaccharides by in vitro chemical simulation experiment,including polysaccharides scavenging free radicals of hydroxyl,2,2-diphenyl-1-picryl-hydrazyl,super-oxide anion and alkyl,reducing power,antioxidant activity and scavenging nitrites.The paper also evaluates the advantages and disadvantages of various test methods and their applications.

Key words: plant polysaccharide, antioxidant, free radical, scavenging capacity