A dust cover assembly including: a dust cover made of resin and having a bellows tube portion; and an upper insulator made of rubber attached to a top end of the dust cover. An engaging tube portion is integrally formed with an upper part of the bellows tube portion of the dust cover. At least one engaging groove opens onto an outer peripheral face of the engaging tube portion and extends in a circumferential direction. At least one locking protrusion is formed on an inner peripheral face of the upper insulator having an annular shape and protrudes toward an inner peripheral side, while extending in the circumferential direction. The engaging tube portion of the dust cover is inserted into the upper insulator, while the locking protrusion is inserted into the engaging groove and is locked therein in an axial direction.