Disclosed herein is a pedal feeling adjusting device. According to an embodiment of the present invention, the pedal feeling adjusting device that adjusts pedal feeling provided to a driver by an oil pressure generated in accordance with pedal effort of the driver, includes a pedal simulator that includes a simulator block in which an oil hole connected to a master cylinder through a flow path is formed on an upper portion thereof to receive the oil pressure in accordance with the pedal effort of the driver and bores are formed therein to contact the oil hole, a damping housing coupled to seal the bores, first and second pistons provided in series in the bores to be compressed by oil and slidably moved, and an elastic member supported by the damping housing and compressed in accordance with movement of the first and second pistons to provide a reaction force, a hydraulic flow path that is connected to the flow path to provide the oil pressure between the first and second pistons, and a control valve that is provided in the flow path to control the oil pressure to be selectively provided to the oil hole or the hydraulic flow path. Here, the first and second pistons are formed to have mutually different diameters.