Abstract: The paper builds a model for piezoelectric intelligent structures and calculates the modal frequency using ANSYS software. The D-optimal design principle is applied and the selected modes are converted into a unitary form by simplifying the principle. Finally, the optimal position of piezoelectric elements can be determined by the mode shapes of the structures solely, thus position’s randomcity will not be introduced. This paper considers the influence of the main structure’s dynamics characteristics produced by the bonded piezoelectric elements, and adopts the Linear Quadratic Gauss (LQG) optimal control method to design a Kalman filter, which can be used to filtrate the process noise and measurement noise. At last, a piezoelectric cantilever beam is taken as an example to prove the effectiveness of the method in this paper.