In a vehicle braking system for stabilizing vehicle behavior: a motor control unit determines whether or not the motor control unit receives a drive forbid signal from a yaw-moment control unit, when the motor control unit receives a drive instruction signal from a vehicle-behavior stabilization control unit. The motor control unit receives the drive forbid signal when the yaw-moment control unit performs yaw-moment control. The motor control unit forbids prepressurization using a slave cylinder, when the motor control unit receives the drive forbid signal.