Abstract: This paper analyses the anterior descending branch of the arteria coronaria sinistra from the view of hemodynamics.The results show that the branching of the anterior descending branch with an angle of 90° at the opening and the formation of the mural arteria coronaria are the hemodynamic characteristics.The shearing stress of the turbulent flow, the additional pressure, the formation of the blood vertex, and the impulsive pressure, caused by these characteristics, are hemodynamic reasons that leads to the occurence of atherosclerosis in anterior descending branch.