An electric brake system comprising: a master cylinder configured to a reservoir storing oil therein and configured to generate hydraulic pressure according to a pedal effort of a brake pedal; a cut valve installed at a backup flow path connecting the master cylinder to a wheel cylinder; a simulation device including a simulation chamber connected to the master cylinder at a front end of the cut valve to provide a reaction force according to the pedal effort of the brake pedal, a simulation valve provided at a flow path connecting the master cylinder to the simulation chamber; a hydraulic pressure supply device configured to operate in response to an electrical signal of a pedal displacement sensor sensing a displacement of the brake pedal, and a damping member provided at a flow path connecting the hydraulic pressure chamber to the front end of the cut valve, wherein the damping member delivers a pressure pulsation generated in the hydraulic pressure chamber to the brake pedal in an anti-lock brake system (ABS) mode.