The characteristics of the Electric Vehicle (EV) traction motor system are different from the traditional industrial motor system, and the noise source are also different with different conditions. Based on the theory of sound intensity, the experiments of noise source identification of the Electric Vehicle traction motor system are research through the measurement at discrete points firstly. The noise source of the whole motor are analyzed in details, and the main noise frequencies is 3600Hz and 5800Hz. The figure of noise source identification with different frequencies received and 1/3 octave to sound intensity and sound pressure as well as the noise spectrum characteristics can be acquired. In addition, according to the experiments, the noise spectrum characteristics of each part of the Electric Vehicle motor system have been established.