For the impaired blood clotting due to massive blood transfusion prophylaxis is to be the best treatment, for measures after its occurreance are often very difficult. As prophylactic treatment, continuous drip infusion of a large amount of hydrocortisone, alternated transfusion of fresh and preserved blood, administration of tissue thromboplastin preparation and ACTH were effective. As thrapy for hemorrhagic tendency, massive infusion of hydrocortisone, administration of tissue thromboplastin preparation, transions of fressh blood or platelets were proved to be effective. For decreased clotting factors in case fibrinolysis. intravenous ε-aminocapronic acid and hydrocortisone were efficacious to depress the fibrinolysis.