A type of supportive measure where an external artificial circulator carries a deoxygenated blood from the patient to an oxygenator a gas exchange device in which the gas exchange takes place. ECMO was developed gradually from cardiopulmonary by – pass. Types of ECMO is said to be two types they are Veno-Venous ECMO and Veno-Arterial ECMO. Veno-Venous ECMO was used only for supporting the lungs and Veno – Arterial ECMO was used for supporting both the lungs and heart. In both the cases blood is withdraw from venous and goes to machine for purifying. In veno arterial blood is returned directly to the aorta and goes to the systemic circulation. At the same time in veno venous after oxygenation the blood is returned to right atrium and circulates in systemic circulation.