Abstract: Aiming at the problems of electromagnetic compatibility (EMC) in electric cars, the electromagnetic environment of a domestic electric vehicle (EV) was studied. The mechanism of common-mode electromagnetic interference (EMI) was discussed thoroughly to analyze the main factors disturbing the function of in-vehicle network and electric appliances. And the models were established for the two main common-mode EMI sources: AC generator rectifier system and pulse width modulation (PWM) inverter, and they were verified by comparing the calculated and experimental results. Based the theory and experiment analysis of the electromagnetic sensibility of CAN, it was showed that the EMI intensity produced in electric vehicle drive system had far exceeded the electromagnetic compatibility of CAN network. Finally, a standard FlexRay was presented for the in-vehicle network as a solution of new generation EVs.