Objective This work is to study the types of polysaccharides， physicochemical characteristics and biological activities of the sea cucumber Ludwigothurea grisea. Methods The polysaccharides were isolated from the body wall of sea cucumber L. grisea. Their multiple physicochemical properties， spectral characteristics and anticoagulant activities were then examined. Results The three types of polysaccharides were found in the sea cucumber L. grisea， and their chemical structures and physicochemical properties are significantly different each other. In addition， fraction LG-1 is a fucan with sulfate ester， the polysaccharide fraction LG-2 is a neutral glucan which contains glucose as the only sugar， and fraction LG-3 iscomposed of glucuronic acid (GlcA)， N-acetylgalactosamine (GalNAc) and fucose， named fucosylated glycosaminoglycan (FGAG). The LG-3 has stronger anticoagulant activities than LG-1， and the LG-2 has no activity. Conclusion The body wall of the sea cucumber L. grisea contains at least three different types of polysaccharides， among which the neutral α-glucan was firstly obtained from sea cucumber. The anticoagulant activities of the different types of polysaccharides may relate to monosaccharide composition and sulfate content.