Abstract: The optimal vibration control in cantilever piping for fluid delivery, which is supported by a linear spring with nonlinear motion restrained was investigated theoretically taking a piezoelectric vibrator as actuator. The considering the extra moment formed due to the extension/contraction of powered piezoelectric actuator, the differential equations of motion of the controlled piping system were derived and then discretized by Galerkin's method. A controller was designed on the basis of optimal regulator theory, i.e., the deflection of pipe and the input energy of control could both be minimized simultaneously, the motional responses to both controlled and non-controlled systems were examined by numerical simulations to verify the validity of the control scheme. The comparison between the results of both systems revealed that the optimal control scheme presented here could control effectively both periodic and chaotic vibrations in the piping system.