PURPOSE: To provide the rear wheel steering device of a vehicle capable of improving the traveling stability by providing a control switching means stopping the feedback control of the steering angle of rear wheels by a yaw rate feedback control means when the turning state detected by a turning state detecting means is sharper than the preset turning state.

CONSTITUTION: In the sharp turning state with large lateral acceleration, the control of the steering angle of rear wheels 3 is switched by a control switching means 33 from the control by a yaw rate feedback control means 30 to the control by a sideslip angle control means 31 controlling the steering angle of the rear wheels 3 in the in-phase direction as the estimated sideslip angle is increased. In the sharp turning state with high lateral acceleration, the rear wheels 3 are surely prevented from being steered in the reverse-phase direction to front wheels to decrease the in-phase quantity. The traveling stability can be improved in the sharp turning state with high lateral acceleration.