The leading causes of death are now diseases that involve heart and bloodvessels and as a consequence thrombosis.Fucosylated chondroitin sulfate(fCS),a glycosaminoglycan isolated from sea cucumber,has received an increased attention due to its distinct anticoagulant and antithrombotic activity.To minimize adverse effects induced by fCSs and obtain a promising anticoagulant,we prepared a series of oligosaccharides by oxidative depolymerization of fCS,and then elucidated the relationship between the structures and the anticoagulant activities and investigated the mechanisms of anticoagulant activity mediated by sulfated oligosaccharides.