Abstract: A reinforcing device for a roof carrier, which includes a reinforcing member having a crossbar for placing and fixing an object to be carried thereon, a pair of stands for supporting the crossbar, the stands having holes extending therethrough, a pair of mounting members separate from the pair of stands and interconnecting the roof and the pair of stands on the roof, a wire made of a flexible material, mounting metal members respectively coupled to opposite ends of the wire, a screw rod projecting outward from each of the mounting metal members, wherein the screw rods extend through the holes formed in the stands in the vicinity of end portions thereof, and first and second clamp nuts engaged with threaded portions of the screw rods and contacting an outer side portion of the mounting members.