Brake hydraulic pressure control system for vehicle

Brake hydraulic pressure is appropriately prevented from becoming lower than a reference brake pressure for holding control. When a physical amount correlating with the rotational speed of an electric motor has become higher than or equal to a predetermined value, an HSA start reference pressure setting unit sets an HSA start reference pressure (B) to a value higher than a reference brake pressure (E), and if the HSA start reference pressure (B) at a time (t3) when a driver required fluid pressure (C) has become lower than the HSA start reference pressure (B) is higher than the reference brake pressure (E), an HSA required fluid pressure setting unit sets an HSA required fluid pressure at a time when the driver required fluid pressure (C) has become lower than the HSA start reference pressure (B) to a value higher than the reference brake pressure.