Abstract: Plant polysaccharides were widely distributed in organisms.They were natural macromolecular polymers linked by aldose or ketose through glycosidic bonds.They were important biological macromolecules in living organisms,one of the basic things in normal operation.Different plant polysaccharides had almost the same monosaccharide composition,but the content of each component varies greatly.Methods of plant polysaccharide’s extraction and separation includes solvent method,enzymatic method,ultrasonic method,microwave method,flash extraction method,ultra-high pressure technology,membrane separation technology and a variety of technologies combined.In practice,different methods can be chosen depending on the specific substance.Plant polysaccharides had a variety of active functions,such as anti-oxidation,anti-aging,anti-fatigue effect,anti-tumor effect,hypoglycemic effect,hypolipidemic effect,immunomodulatory effect,antibacterial and antiviral effect,and some other functions such as prevention of liver injuried,anti-radiation,anti-mutation and so on.

Key words: plant, active polysaccharide, monosaccharide composition, extraction, separation, active function