Abstract: A power steering apparatus, including a pump, a power cylinder, a control valve and a switching valve. The switching valve is for connecting the cylinder chambers in accordance with pressure change of the operating fluid responsive to operation of the control valve in order to return the steering wheel toward a neutral position. When the rotation of the steering wheel is substantially stopped, the switching valve reacts to the pressure change in order to connect the cylinder chambers, so as that the higher hydraulic pressure of one of the cylinder chamber releases to the other. This hydraulic pressure releasing of the operating fluid returns the power piston toward the neural position, smoothly. The steering wheel also returns toward the neutral position in accordance with the return of the cylinder piston, so as that restoring force of the steering wheel is enhanced.