This paper describes the vibration suppression of torsional systems of finite degrees-of-freedom (DOF) by using the wave absorbing control method with online computation of a virtual wave propagating system that is similar to the real system to be controlled. This method makes up a wave-absorbing damper as the virtual system is always in wave propagating state. The basic concept of the control method was formerly presented for a multiple pendulum system to suppress free vibrations by one of the authors. In this paper forced vibrations are targeted. The presented method has shown to work well on the forced vibration as on the free vibrations. In order to obtain suitable parameters of the virtual wave propagating system, the theoretical analysis on wave propagation of a homogeneous spring-and-disc system has been conducted. And we got the fact that wave absorbing control can be conducted below the frequency of 2√(k/I), where k is spring constant and I is moment of inertia of disc. Experiments are conducted on 1-, 2- and 3-DOF systems.