Abstract: The permanent magnet synchronous motors（PMSM） is widely adopted for traction motor in the electric vehicles（EV） with the advantage of high efficiency and high torque density.Field oriented control（FOC） is appropriate for PMSM and the maximum efficiency control can be achieved.In this paper,the principle for electric braking control of PMSM under FOC was studied.Based on this,the optimal regenerative braking control strategy for EV was obtained with the model of the electric drive system（including PMSM,inverter and battery）,which was significant for the economical operation of EV.In the existing electrical and mechanical coupling braking methods of EV,the parallel and the series braking control strategies were compared.The results showed that the optimal regenerative braking was achieved in the series braking control strategy and a good regenerative braking could be obtained by adjusting the free travel of mechanical brake appropriately with the parallel braking control strategy.