Clinically anticoagulant drugs can prevent thrombotic disorders. The following anticoagulant drugs are commonly used: i. Antiplatelet drugs, such as aspirin, dipyridamole (Pansentin), clopidogrel, etc., are commonly used to prevent coronary heart disease, cerebral thrombosis and other diseases. Second, bicoumarins anticoagulant drugs, the most commonly used is warfarin, which is a competitive inhibitor of vitamin K. By affecting the absorption of vitamin K and play an anticoagulant effect, clinically commonly used in rheumatism patients after valve surgery to prevent thrombosis. Third, the heparin class of anticoagulant drugs, there are two categories of ordinary heparin and low-molecular heparin, it is through the inhibition of thrombin II, the role of coagulation factor X to play the anticoagulant effect, can be used to prevent venous thrombosis of the lower extremities, as well as the treatment of diffuse intravascular coagulation.