To provide a coupling supporting device which supports upper and lower couplings with a remarkably simple structure and which executes the working of roll set change speedily.

These devices are supporting devices which position oppositely at end faces of the axial direction of upper and lower roll chocks 4, 5 assembled in a housing of a rolling mill and which receive upper and lower pairs of couplings to connect driving spindles to rolls held with the roll chocks 4, 5, a pair of supporting devices 11, 12 of respectively and individually moving up and down are arranged on the positions of upper side and lower side of the couplings 7, 8, in the supporting device 11 arranged on the upper side, the upper coupling 7 is held in the state of hanging up the upper coupling, in the supporting device 12 arranged on the lower side, the lower coupling 8 is received, mounted and held respectively. Further, by providing a magnet 11c to attract and hold the coupling 7 on the supporting device 11 arranged on the upper side, the coupling is held only with the raising and lowering action of the supporting device.