The invention is directed to an arrangement for controlling a braking force applied to a rear wheel in a certain relationship with a braking force applied to a front wheel, so as to provide an ideal braking force distribution. Pressure control valves are disposed in a hydraulic circuit which communicates a master cylinder with at least a rear wheel cylinder. There are provided an auxiliary power source for discharging a power pressure and a hydraulic booster for regulating the power pressure and actuating the master cylinder. A changeover valve is disposed between the master cylinder and the control valves, and selectively placed in one of a first operating position for communicating the control valves with the master cylinder and blocking the communication between the control valves and the hydraulic booster, and a second operating position for communicating the control valves with the hydraulic booster and blocking the communication between the control valves and the master cylinder. When the changeover valve is placed from the first operating position to the second operating position, the control valves control the hydraulic pressure in the rear wheel cylinder in a certain relationship with the hydraulic pressure in the front wheel cylinder.