In this paper, the system simulation of a fixed O. W. C. type wave energy absorber is proposed, which takes into consideration the interaction between the O. W. C. and the turbine. In the present simulation, the coefficients of turbine system show a nonlinear characteristic against the flow velocity and the revolutions per minute of turbine, so that a time stepping procedure is applied to the analysis. Both equations of motion of O. W. C. and the turbine are solved simultaneously. The turbine reaction and the generated powe are obtained.