A basic pulsatile-flow model of the circle of Willis at the base of the brain was built with integrated lumped circuits. The non-steady Navier-Stokes equation and one other equation which governs the radial movement of the distinsible walls were applied to each of the 22 consecutive short segments into which the circle of Willis was subdivided. The segments were so arranged that the regions where circulation would be influenced by local increase of resistance or altered field of blood supply were located at junctions of the segments. Direct measurement of intravascular blood pressure from a dog's carotid artery was taken to test the model performance. The computer model compared favorably with the data measured from the animal prototype.