Natural polysaccharides are safe and low-toxic,and are potential drugs for the treatment of diabetes.In order to find plant polysaccharide resources with high activity and high content,Dendrobium wardianum Warner,D. officinale and D. nobile were compared in terms of yield,structure and hypoglycemic activity of polysaccharides.Polysaccharides were obtained by hot water leaching,dialysis and chromatography,and then the hypoglycemic activity was measured using a diabetic mouse model.The results showed that D. wardianum had a highest polysaccharide yield (14.1%,DW).DWCP had the lowest molecular weight and its monosaccharide composition is similar to DOPP.The hypoglycemic activity of DWCP was significantly better than the other two polysaccharides.It indicated that D. wardianum could be used as an excellent parent,which provides breeding resources for the development of hypoglycemic polysaccharide resources.