A hydraulic pressure control unit of a braking system mountable on a bicycle and capable of executing an antilock braking control, the hydraulic pressure control unit comprising: a base body in which a master cylinder port to which a liquid pipe communicating with a master cylinder is connected, a wheel cylinder port to which a liquid pipe communicating with a wheel cylinder is connected, and an internal flow path for communicating the master cylinder port and the wheel cylinder port with each other are formed; and an inlet valve and an outlet valve which are attached to the base body and opened and closed when the antilock braking control is executed, wherein the master cylinder port is formed in a first surface of the base body, and the wheel cylinder port is formed in a second surface facing the first surface of the base body, and wherein the inlet valve is driven by a first coil, the outlet valve is driven by a second coil, and the first coil and the second coil are erected on a third surface of the base body, whose both ends reach the first surface and the second surface, characterized in that the hydraulic pressure control unit further comprises: a circuit board electrically connected to at least one of the first coil and the second coil, wherein the circuit board is held in a state where a mounting surface of the circuit board extends along a direction in which the first surface and the second surface are arranged, a connector electrically connected to the circuit board, wherein the connector is erected in a direction different from the direction in which the first surface and the second surface are arranged, and an accumulator for storing brake liquid flowing through the internal flow path, wherein the accumulator is provided on the second surface of the base body, and in a state where the mounting surface of the circuit board is viewed from the front, the connector is located on the side where the first surface is located with respect to the first coil and the second coil. a base body in which a master cylinder port to which a liquid pipe communicating with a master cylinder is connected, a wheel cylinder port to which a liquid pipe communicating with a wheel cylinder is connected, and an internal flow path for communicating the master cylinder port and the wheel cylinder port with each other are formed; and an inlet valve and an outlet valve which are attached to the base body and opened and closed when the antilock braking control is executed, wherein the master cylinder port is formed in a first surface of the base body, and the wheel cylinder port is formed in a second surface facing the first surface of the base body, and wherein the inlet valve is driven by a first coil, the outlet valve is driven by a second coil, and the first coil and the second coil are erected on a third surface of the base body, whose both ends reach the first surface and the second surface, a circuit board electrically connected to at least one of the first coil and the second coil, wherein the circuit board is held in a state where a mounting surface of the circuit board extends along a direction in which the first surface and the second surface are arranged, a connector electrically connected to the circuit board, wherein the connector is erected in a direction different from the direction in which the first surface and the second surface are arranged, and an accumulator for storing brake liquid flowing through the internal flow path, wherein the accumulator is provided on the second surface of the base body, and in a state where the mounting surface of the circuit board is viewed from the front, the connector is located on the side where the first surface is located with respect to the first coil and the second coil.