The present invention discloses use of sea cucumber glycosaminoglycan in the preparation of drugs. In particular, the present invention relates to use of medical use of sea cucumber glycosaminoglycan, and more particularly to use of depolymerized sea cucumber glycosaminoglycan or natural molecular segments of sea cucumber glycosaminoglycan with a weight average molecular weight greater than 54,500 Da in the preparation of a drug for the prevention and treatment of thromboembolic diseases. Thromboembolic diseases include atherosclerotic thrombotic diseases, venous thromboembolic diseases, hypercoagulable states and postoperative thrombosis or treatment of postoperative thrombi. The present invention has a wide treatment window for thromboembolic diseases, has a higher level of safety, and has good development and research value.
