In a vehicle steering system, in particular a steer-by-wire system, using a feedback
control including an integral control unit in the feedback path, the integral factor
of the integral control unit is made variable depending on the condition of the
vehicle, road condition and preference of the vehicle operator so that the intensity
of the steering reaction from the tires that is applied to the vehicle operator
can be optimally adjusted. Thereby, the steering system can reduce the stead-state
deviation and improve the stability in holding a steering angle both without any
substantial compromise.