Disclosed is an electronic braking system and operation method thereof. The electronic braking system and operation method thereof includes a hydraulic pressure supplier configured to create hydraulic pressure by moving a hydraulic piston based on an electric signal output to correspond to displacement of a brake pedal, and a hydraulic controller configured to control hydraulic pressure of a pressure medium applied to each wheel cylinder, and performs normal operation mode, abnormal operation mode, regenerative braking mode, and check mode by controlling a plurality of valves equipped in the hydraulic controller.