A brake hydraulic pressure control system for vehicle comprising: a brake operation element; an operation amount detecting unit for detecting an operation amount of the brake operation element; an electric motor that is driven, based on the operation amount detected by the operation amount detecting unit; a piston (88a, 88b) that operates forward and backward, accompanying rotation of the electric motor; a wheel cylinder (32FL, 32RR, 32RL, 32FR) for braking wheels by a brake hydraulic pressure corresponding to a displacement amount of the forward and backward operation of the piston, a holding-control start reference pressure setting unit for setting a holding control start reference pressure serving as a threshold value for starting holding control, based on a reference brake pressure that is necessary for maintaining a stop state of the vehicle, a holding-control required fluid pressure setting unit for setting a holding control required fluid pressure serving as a target fluid pressure after starting the holding control; and an offset pressure setting unit for setting an offset pressure to be added to the reference brake pressure; wherein the offset pressure setting unit sets the offset pressure, corresponding to a physical amount being an amount of change per predetermined time in a driver required fluid pressure that is a brake hydraulic pressure required by a driver and correlating with the rotational speed of the electric motor, wherein the holding control start reference pressure is set to a magnitude obtained by adding the offset pressure having been set by the offset pressure setting unit to the reference brake pressure; wherein the displacement amount of the piston (88a, 88b) is controlled by the electric motor in order to perform the holding control, based on the reference brake pressure, and wherein, if the physical amount correlating with a rotational speed of the electric motor has become greater than or equal to a predetermined value, the holding control start reference pressure is set higher than the reference brake pressure, and when the driver required fluid pressure has become lower than the holding control start reference pressure, the holding-control required fluid pressure setting unit sets the holding control required fluid pressure at a time when the driver required fluid pressure has become lower than the holding control start reference pressure, to a value higher than the reference brake pressure. a brake operation element; an operation amount detecting unit for detecting an operation amount of the brake operation element; an electric motor that is driven, based on the operation amount detected by the operation amount detecting unit; a piston (88a, 88b) that operates forward and backward, accompanying rotation of the electric motor; a wheel cylinder (32FL, 32RR, 32RL, 32FR) for braking wheels by a brake hydraulic pressure corresponding to a displacement amount of the forward and backward operation of the piston, a holding-control start reference pressure setting unit for setting a holding control start reference pressure serving as a threshold value for starting holding control, based on a reference brake pressure that is necessary for maintaining a stop state of the vehicle, a holding-control required fluid pressure setting unit for setting a holding control required fluid pressure serving as a target fluid pressure after starting the holding control; and an offset pressure setting unit for setting an offset pressure to be added to the reference brake pressure; wherein the offset pressure setting unit sets the offset pressure, corresponding to a physical amount being an amount of change per predetermined time in a driver required fluid pressure that is a brake hydraulic pressure required by a driver and correlating with the rotational speed of the electric motor, wherein the holding control start reference pressure is set to a magnitude obtained by adding the offset pressure having been set by the offset pressure setting unit to the reference brake pressure; wherein the displacement amount of the piston (88a, 88b) is controlled by the electric motor in order to perform the holding control, based on the reference brake pressure, and wherein, if the physical amount correlating with a rotational speed of the electric motor has become greater than or equal to a predetermined value, the holding control start reference pressure is set higher than the reference brake pressure, and when the driver required fluid pressure has become lower than the holding control start reference pressure, the holding-control required fluid pressure setting unit sets the holding control required fluid pressure at a time when the driver required fluid pressure has become lower than the holding control start reference pressure, to a value higher than the reference brake pressure.