In regenerative braking, the kinetic energy of the vehicle is stored in a battery as the electric energy that is otherwise being dissipated as heat by friction, so that the stored energy is recuperated to drive the vehicle. In general, another independent braking mechanism, such as hydraulic brakes, needs to be used in cooperation with regenerative braking in order to meet the total braking force demand. The smart booster system, which uses a permanent magnet synchronous motor to replace the conventional vacuum booster, is proposed in this paper as an active braking system which is well suited for such regenerative cooperative braking applications in environment friendly vehicles. A pressure feedback control is used with a nested current control loop using pressure and current sensors, respectively. Two types of smart booster systems are investigated for different applications, and the samples of both types of smart booster systems are built to check the feasibility of the proposed systems.