A mathematical model of pulsating flow in a tapered rigid artery with an axially symmetric stenosis is established. The incompressible Navier-Stokes equation for the flow field is solved numerically and a finite difference scheme is used to implement the numerical calculation. The distributions of the wall shear stress with three stenosis severity (h/R₀=1/4,1/3,1/2) are provided and discussd.The stream function contour with h/R₀=1/3 is given. The result shows that the stenosis disturbs the flow flied in the vicinity of the stenosis, especially at the throat and in the downstream.