Regenerative braking, which can effectively improve vehicle's fuel economy by recuperating the kinetic energy during deceleration processes, has been applied in various types of electrified vehicle as one of its key technologies. To achieve high regeneration efficiency and also guarantee vehicle's brake safety, the regenerative brake should be coordinated with the mechanical brake. Therefore, the regenerative braking control performance can be significantly affected by the structure of mechanical braking system and the brake blending control strategy.By-wire brake system, which mechanically decouples the brake pedal from the hydraulic brake circuits, can make the braking force modulation more flexible. Moreover, its inherent characteristic of ‘pedal-decouple’ makes it well suited for the implementation in the cooperative regenerative braking control of electrified vehicles.With the aims of regeneration efficiency and braking performance, a regenerative braking control algorithm for electrified vehicles equipped with a brake-by-wire system is researched in this paper. The layout of the adopted brake-by-wire system is introduced. The proposed regenerative braking control algorithm is illustrated. To validate the control performance of the algorithm, hardware-in-the-loop simulations are carried out. The simulation results show that, based on brake-by-wire system, the proposed control algorithm, coordinating regenerative brake and hydraulic brake well, can further improving the regeneration efficiency of electrified vehicle and guarantee the braking performance in the meantime.