In order to estimate the vibration and acoustic noise in a permanent magnet (PM) Synchronous Motor, the
natural frequencies of the stator structure should be determined during the design stage. In this paper, analytical formulas to predict the natural frequencies of the stator are derived. The analytical model of the stator includes stator teeth, winding, stator core, and stator case. It is observed that the natural frequencies calculated with the integrated components exceed those based on the stator core alone only. In order to verify this analytical model, numerical simulation and experimental measurement are carried out using a PM Synchronous motor which has 5 pole-pairs and 12 slots structure configuration. Good agreement are observed among the results obtained by analytical formula, simulation and experiment.