To reduce the limitation imposed on the processing of a valve mecha nism, and thereby attempt to reduce costs.

This fluid pressure control device is so constituted as to be equipped with a valve mechanism 5 which reduces the fluid pressure of a master cylinder by a specified ratio, and transmits it to each rear wheel brake cylinder, and with a load detection mechanism 7 which applies load corresponding to live load to a planger 51, and shifts the starting point for a decompressing action of the valve mechanism 5. In this case, in order to press the valve body 10 of the valve mechanism 5 to the direction of valve opening, the end part of the planger 51 abutting against the valve body 10 is formed integrally with the planger 51, furthermore, a small diameter pressing part 51b extended in the direction of a planger shaft, and a fluid pressure passage are formed in the radial direction from the direction of the end of the planger, and the end part of the planger is formed out of a collar member 52 coaxiall-y pressed in the small diameter pressing part 51b.