In a hydraulic braking pressure control apparatus disposed in an oil passage transmitting a hydraulic pressure outputted from a master cylinder to a wheel brake and adapted to control the transmission of that hydraulic pressure when a wheel is about to be locked, there are provided a first valve mechanism adapted to cut off, only during the supplying of a liquid pressure into a control chamber, the communication between an input hydraulic chamber adapted to receive a hydraulic pressure from the master cylinder and an output hydraulic chamber adapted to supply a hydraulic pressure to the wheel brake in accordance with the input hydraulic pressure, and a second valve mechanism adapted to bring the input and output hydraulic chambers, which are disconnected from each other upon the supply of the liquid pressure, into communication with each other when the hydraulic pressure in the output hydraulic chamber has been reduced less than a predetermined value.