Abstract: In China,plant resources are abundant,which lays solid material foundation for the development and utilization of plant polysaccharides. Natural plant polysaccharides belong to a very important class of biological macromolecules in plants,and they are the basic substances which effectively maintain and ensure the normal operation of biological life activities. They have various pharmacological effects such as anti-tumor,immune regulation,anti-viral and anti-oxidant activity. They can be used as natural immunomodulator. These studies have become one of the research hotspots of scholars at home and abroad. This article reviews the recent research progress on pharmacological effects of plant polysaccharides on immune regulation,anti-tumor,anti-viral,anti-oxidant,blood pressure,anti-thrombotic,hypoglycemic,protection against immune liver injury,and anti-radiation activity. It is hoped to provide a good theoretical basis for the better development and utilization of plant polysaccharides and their wide application in related fields such as medicine and food.