PURPOSE: To effectively lower road noise even when oscillation having frequency close to the resonance point of an unsprung rigid body is inputted to wheels from the road surface.

CONSTITUTION: This invention is concerned with a suspension arm 30 which is rotatably pivoted by a wheel support member at its one end, and is pivotally supported by a body at the other end. The portion of the suspension arm between its one end and the other end is off-set to the direction perpendicularly intersected with a straight line 56 connecting the center P of a joint 26 at one end and the center Q of a joint 34 at the other end. Besides, the bending stiffness distribution or the mass distribution of the suspension arm is so set that the wave trough area of axial force transmission characteristics for the suspension arm includes the resonance point of an unsprung rigid body applicable for the case that the aforesaid off-set is zero.