PURPOSE: To provide a construction of a coupling device capable of converting easily by providing an automatic converter operated by air source.

CONSTITUTION: In a coupling device for railway rolling stock comprising a coupling 2 and a rubber shock absorber 3, a guide rail 4 and a pulley 8 are provided to make it in storing system, an automatic converter 6 comprising a valve, an electromagnetic valve, and an air cylinder is provided for storing the coupling device, and also a winding drum 7 is provided so that manual converting can be made by cutting off air source by the operation of the valve. This has an effect to make conversion of the coupling device easily and automatically. Also, if the automatic converter 6 fails, it can be converted manually by cutting off air source.