Objective To study the distributions of velocity and pressure of blood within the aortic arch under normal physiological pulsatile flow conditions in order to provide fundamental theories for the genesis of an arteriosclerosis and its prevention. Method By virtue of the CFD and the fundamental of hemodynamics,the paper gives numerical simulations and flow visualizations of pulsating blood flow in the aortic arch with a tapered angle. Results The distributions of velocity,pressure and path line for the blood flow of the aortic arch with a tapered angle are obtained as a function of time in the cardiac circle. Conclusion There are a lot of causes which result in the complications of pulsating blood flow in the aortic arch.The most important two causes among them are the tapered angle and the curvature of the aortic arch.