The objective of this chapter is to introduce the cardiovascular system. Cardiovascular system is a transport system to carry blood and lymph to and from the tissues of the body. This system has three main components such as the heart, the blood vessel and the blood itself. Two types of circulation are systemic circulation and pulmonary circulation. Systemic circulation conveys blood from heart to tissues and vice versa. Pulmonary circulation conveys blood from heart to lungs and vice versa. Clinical images are also provided in the chapter.