Disclosed is a pressure damping device for a brake system. The pressure damping device is installed at the brake system having a hydraulic block provided with a first hydraulic circuit to control transfer of fluid pressures generated by a first port of a master cylinder and discharged from a first pump to a first wheel, and a second hydraulic circuit to control transfer of fluid pressures generated by a second port of the master cylinder and discharged from a second pump to a second wheel, and the hydraulic block includes a bore connecting the master cylinder with discharge outlets of the first and second pumps and formed between first and second main oil paths to communicate with the first and second main oil paths, and a pressure damping unit provided in the bore and having a volume changed according to the fluid pressures from the first and second pumps.