The present invention provides a mounting structure for the vehicle auxiliary mirror, including an attachment plate enabling said auxiliary mirror to be attached to the rear-view mirror, at least one first hook configured on the edge of said attachment plate corresponding to the mirror frame opening of the rear-view mirror and allowed to hook the abutting mirror frame opening of the rear-view mirror, a fixing belt with one end fastened to the housing of said auxiliary mirror disposed on the middle of the rear face of said auxiliary mirror and adjustable in length, and a second hook secured to the other end of said fixing belt and allowed to hook the rim of the rear-view mirror frame opening opposite to the rim hooked by the first hook via the rear face of the rear-view mirror, so that said auxiliary mirror may be tightly attached to the rear-view mirror.