An automotive hydraulic brake system is provided which exhibits an excellent pressure reduction performance to a low μ road while restraining an intake resistance of a fluid pump. For providing the hydraulic brake system, a gate-in valve is connected to an intake passage that connects a master cylinder to an intake side of the fluid pump. The gate-in valve selectively opens and closes the intake passage in accordance with a mutual relation between a master cylinder pressure and a pressure produced at an intake side of the fluid pump.