To suppress a pressure loss in a pressure transmission path and adequately carry out a pressure regulation and supply pressure to an aiding chamber or the like in a vehicular hydraulic brake device equipped with a pressure regulation valve means and the aiding chamber.

The vehicular hydraulic brake device is provided with a pressure regulation valve means 30 which introduces a fluid pressure of output power of an auxiliary fluid pressure source to a first pressure regulation chamber C1 formed forwardly of a control piston 20 and regulates the fluid pressure to a predetermined pressure in accordance with movement of the control piston. A second pressure regulation chamber C2 is formed forwardly of the pressure regulation valve means and the first pressure regulation chamber C1 is directly communicatingly connected with the second pressure regulation chamber and the aiding chamber C3 through a common communicating path. For example, a communicating path P0 in an axial direction which is in parallel with a cylinder hole 3 and communicates with the aiding chamber C3 is formed as a common communicating path. A first diametrical direction communicating path P1 opening to the first pressure regulation chamber and a second diametrical direction communicating path P2 opening to the second pressure regulation chamber are formed to communicate with the communicating path P0.

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