Heparin sodium could not be absorbed orally, and it took effect 3min after intravenous injection, with the maximum effect time of 2-4h and half-life of about 2h. Subcutaneous injection after 2~4h effect, the maximum effect time is 3min, peak time is 3~4h, half-life is about 3~5h, bioavailability is 87%, after multiple administration, the effect can be maintained 10~24h. Give full play to the activity of anti thrombosis in plasma treatment of anti - Ⅹ a needed concentration range between 0.1 ~ 0.6 U/ml. To prevent left ventricular thrombosis in patients with acute anterior wall myocardial infarction, the resistance of heparin sodium - Ⅹ a blood drug concentration of 0.6 ~ 1.0 U/ml; The treatment of acute venous thrombus average shape form is needed for the formation of anti - Ⅹ a blood concentrations of 0.5 U/ml. The distribution of heparin sodium in vivo is less extensive than that of unfractionated heparin, and its distribution volume (Vd) is 40~60ml/kg or 3~11L. Heparin sodium is excreted mainly by the kidney, and its renal clearance rate is 20~30ml per minute.