In this paper, we propose a method to suppress shaft voltage by changing the shape of the permanent magnets in the Interior Permanent Magnet (IPM)-type high voltage motors. The shaft voltage, which is induced by parasitic components and leakage flux in the motor driven system, adversely affects their bearings. For minimizing the shaft voltage, a magnet re-arrangement of the motor are designed. The suppression effect of the shaft voltage of the designed model is confirmed by comparing FE analysis and experimental results.