The impedance properties of a wave transmission line containing viscous liquid are experimentally investigated. The pulsating flow rate is measured with an accelerometer connected to a light piston placed at the inlet of a pipe with a closed end. There is good agreement between the experimental results and the theoretical ones given by the axisymmetrical viscous wave equations. Another wave equations considering also a radial pressure gradient are introduced to explain the transition of velocity profile in front of the piston. As the result it is thought the the influence of the piston interposed in oil column decreases rapidly with an increasing distance from it, and is negligible for the present purpose. According to the equations proposed here, dynamic pressure and flow rate in a circular liquid pipe are expressed in infinite series with respect to eigenvalues. A numerical procedure to obtain the eigenvalues for oscillation is developed, too.