Abstract: If the transmural pressure of a latex tube containing pulsatile flow is negative, the tube will collapse with its cross-sectional area and moment of inertia decreasing. At first, this paper derived the governing equation of the related problem, that is, the Ma bieu equation with damping and then solved to by the method of strained coordinates in the theory of singular perturbation. It is verified that the periodic change of cross-sectional area and moment of inertia enforces the excitation of the pulsatile ...