In this paper, the underlying anhysteretic polarization is quantified through constitutive equations derived using Boltzmann statictics and Langevin model. The remanent polarization and the irreversible polarization are analyzed. A thermodynamic description of ferroelectric phenomena is proposed to address the coupling relations between electrical field and mechanical field by considering the series expansion of the elastic Gibbs energy function. A simple linear mapping hysteresis model based on theory of microscopic polarization is derived. In order to evaluate the effectiveness of the proposed model, a micro-positioning stage driven by the PZT in open-loop operation was used to test. The experimental results show that the proposed hysteresis model could precisely describe hysteresis phenomena. The fitting error is within 0.5%.