A vehicle steering system includes: a steering actuator (M) that imparts a steering force to a steering mechanism (1) of a vehicle; an automatic steering controller (10) that performs an automatic steering control by controlling the steering actuator (M); a driving state detector that detects a driving state of the vehicle during the automatic steering control; a threshold value setting unit that variably sets a threshold value for permitting an intervention in the automatic steering control; and an automatic steering intervention unit that intervenes in the automatic steering control based on a threshold value set by the threshold value setting unit.
