Heparin is a sulphated natural mucosaccharide, widely existing in human and mammalian tissues, with anticoagulant effect. Heparin is produced by mast cells close to blood vessels and often exists in the form of proteoglycan units. Its chemical structure is composed of dexglucuronic acid and dexglucosamine, with a molecular weight distribution of 5000-30000 and an average molecular weight of 20000.

　　Heparin for clinical use is extracted and purified from the mucosa of the small intestine of healthy pigs. Sodium salt and calcium salt of heparin are usually used clinically, mainly heparin sodium.

　　Heparin has strong anticoagulant and antithrombotic functions, that is, inhibition of Xa and ⅱ A. Heparin anticoagulant mechanism is relatively unique, mainly through and antithrombin Ⅲ Ⅲ (AT) the combination of inhibition prothrombin activation and thrombin formation and activity, thus promote the dissolution of fibrin (blood clots), and by inhibiting platelet adhesion and aggregation, indirect influence the release of platelet clotting factor within, so it is in the human body and the human body has anticoagulant effect.

　　In addition to anticoagulant and antithrombotic functions, heparin also has many biological functions, such as lowering blood lipid, anti-atherosclerosis, anti-smc proliferation, anti-inflammation, anti-allergy, anti-virus and anti-cancer. Therefore, heparin is widely used in medicine and has a good therapeutic effect on many diseases. In addition to direct clinical use of heparin anticoagulant, antithrombotic, but also the production of molecular heparin and other heparin derivatives of raw materials.