In this paper, the equivalent circuit model of a multilayer piezoelectric transformer (MPT) has been proposed and MPT has also been fabricated using PMS-PZT to investigate the load and frequency characteristics. The model taking into account the loss and the shift of resonant frequency due to the change of a stiffness caused from the lamination is developed based on Mason's equivalent circuit. The symbolic expressions were derived from the model. To verify the accuracy of the proposed equivalent circuit model, MPT have been simulated. The simulation results have been compared with the experimental data. They are shown to agree well over a wide range of various frequency and the load resistance.