Abstract:Microbial polysaccharides are a kind of natural polymers with antioxidant， anti-tumor，immunomodulation and other bioactivities，which have attracted many researchers.Exopolysaccharides such as gellan gum，xanthan gum have been widely used in agriculture，medicine，food and other fields due to their good properties and convenience of obtaining.Among cell wall polysaccharides，lipopolysaccharides and peptidoglycans are with many potential functions in which have considerable value of exploitation and utilization.The paper summarized the structure，properties and existing application of common microbial polysaccharides，and discussed the future development of microbial polysaccharides.