Plasma is the remaining liquid part of whole blood after removing blood cells. The components of plasma include water and various inorganic ions such as potassium ions, calcium ions, sodium ions, sodium ions, etc., as well as various coagulation factors, fibrinogen, and various antibodies, albumin, etc., so plasma has very important roles to play. Common roles are: i. Maintaining the colloid osmotic pressure of plasma, which is mainly achieved through albumin, is to adsorb water inside the blood vessels without penetrating outside the blood vessels, and if the plasma albumin concentration decreases and the colloid osmotic pressure decreases, tissue edema will occur. Second, plasma also has a hemostatic effect, because plasma is rich in clotting factors, which has a very important role in the hemostatic function of the human body, and a decrease in the concentration of clotting factors, the human body will experience the symptoms of bleeding. Third, plasma also has a significant role in enhancing immunity, because plasma contains a large amount of globulin, which can significantly increase the immunity of the human body.