A micropositioning system using a piezoelectric actuator has very wide application region such as an ultra-precision machine tool, optical device, measurement system. In order to keep a high precision displacement resolution, it uses a position sensor and feeds back the error. In this paper, we focused on a model of piezoelectric actuator and simulation of its dynamic behavior. The nonlinear system parameters which can be calculated from its hysteresis loop are considered and an error compensation method using piezoelectric voltage is also suggested.