PURPOSE: To improve degree of freedom as for caster control and camber control by arranging the axis of the bush of the upper fitting part of an upper arm so as to be inclined against the axis of the bush of the base end fitting part of a lower arm.

CONSTITUTION: The bush of the base end fitting part of a lower arm 50 and the bush of the upper fitting part of an upper arm 40 are respectively constituted so as to have the axes B, C in the longitudinal direction of a vehicle body, and the axis C of the bush of the upper fitting part is arranged to be inclined against the axis B of the bush of the base end fitting part. In case of bumping or rebound, caster angle is changed according to oscillation of the upper arm 40 itself. Therefore, the degree of freedom for caster control and camber control can be improved.