Abstract:Polysaccharides are a type of natural macromolecular compounds which are composed of monosac－ charides and form cell membranes of high plant and animal， and cell walls of microbial. They are obtained by the methods of water extraction， alkali extraction， acid extraction method and so on. Plant polysaccharides pos－ sessed some biological activities， such as antitumor， antivirus， antioxidation， antiaging， antidiabetics， and the effective constituent can be used in all sorts of medicines and health products. Therefore， the market prospects of the edible medicinal plant polysaccharides will be very broad.