the one character of Inner Permanent Magnet Synchronous Motor (IPMSM) is that quadrature axis inductance parameter variation is relatively larger than direct axis inductance parameter variation. So in the whole control areas, namely, constant torque and constant power region, the magnetic saturation exerts an important influence on the motor parameters. This paper built a flux-weakening controlling model of IPMSM, and simulated two cases, considering the magnetic saturation and without considering it. Based on those results, the effects of the motor magnetic circuit changes on the motor output properties are analyzed.