PURPOSE: To provide an alignment adjusting device for double wishbone suspension whereby the reliability of construction can be maintained and the adjustment work of camber angle and caster angle can be made easily.

CONSTITUTION: In a double suspension, an eccentric cam mechanism 9 which moves a rubber bush 8 adjustably in lateral direction of a vehicle is provided between rubber bushes 8 and fender aprons 11 connected to the front and rear inner ends of an upper amt 7. Because the eccentric cam mechanism 9 is installed at the upper arm 7 to which a small load is applied from a wheel 2, a load applied to the eccentric cam mechanism 9 is reduced, reliability of construction is increased, lifting up of a vehicle body is not required since an adjusting part is located over the vehicle body, and thus a workability can be increased.