In order to evaluate closed loop performances of the composite plates with distributed piezoelectric actuators, it is essential to obtain more exact system parameters such as natural modes, damping ratios, and modal actuation forces. In this paper a refined analysis of composite plates with distributed piezoelectric actuators for vibration control has been performed. The in-plane displacements through the thickness have been modeled using the layerwise theory. This layerwise model can describe more refined strain distributions and has the capability of more realistic modeling of boundary conditions. The finite element method based on the developed mechanics has been formulated. The constitutive equations for piezoelectric materials have been used to determine piezoelectric actuation forces, and the modal strain energy method has been applied to analyze the damping capacity of the structures. Through the comparison of present results with those available, the accuracy of the present method was verified. The closed loop performances have been evaluated using the simple control algorithms. Through the comparison of present results with those based on shear deformation plate theory, it is concluded that the developed model can describe more realistic smart composite plates with distributed piezoelectric actuators. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.