A shelf assembly mounting structure for a refrigerator includes stoppers respectively provided on both sides of a shelf assembly, a plurality of supporting ribs respectively provided on both side surfaces of a storage space, the supporting ribs being formed to extend in a fore and aft direction of the storage space to support a bottom surface of the shelf assembly; and a plurality of guide slots respectively provided in upper surfaces of the supporting ribs, the stopper sliding in the guide slot in a state where the stopper is positioned therein when the shelf assembly is moved in the fore and aft direction of the storage space. The stopper is moved in the fore and aft direction along the guide slot and brought into contact with front and rear ends of the guide slot, whereby a moving distance of the shelf assembly is restricted.