This paper presents a high frequency (HF) model of electric motor which has high accuracy at frequency range from 100 Hz to 2 MHz. In this model, a series RLC branch is introduced and with the influence of which, the performance of the high frequency range (100 kHz~2 MHz) of the model has been changed. With the comparisons of simulation and experiment results, it is verified that this model improves the performance of the calculated common-mode (CM) impedance at the high frequency range significantly.