An electronic brake system may include a hydraulic pressure supply device having a motor configured to be operated by receiving an electrical signal from the pedal displacement sensor when the brake pedal is operated, a gear pump configured to discharge and suction a hydraulic pressure depending on a rotational force of the motor, and a power transmission unit configured to deliver the rotational force of the motor to the gear pump; a hydraulic control unit having first and second hydraulic circuits configured to receive the hydraulic pressure by a force generated by the hydraulic pressure supply device to control hydraulic pressure flows delivered to wheel cylinders provided on wheels; and an electronic control unit configured to control the motor and valves based on hydraulic pressure information and pedal displacement information.