The paper proposes a design strategy to reduce torque ripple in interior permanent magnet synchronous motor (IPMSM) with concentrated winding. Authors propose there ideas of design strategy. The first is to choose the combination of poles number and slots number which minimizes the torque ripple. The second is the decision of pole arc angle by trapezoidal waveform approximation of the air-gap magnetic flux density. The third is adoption of a unique rotor outer shape to reduce torque ripple. In verification by FEA, the authors succeeded in designing the motor with a high-quality torque characteristic which hardly generates the cogging torque and the torque ripple in the load operation. Efficiency of the proposed motor is almost equal to the conventional IPMSM.