A heat-radiating structure of a cylindrical battery cell includes a first plate configured to contact an upper partial area of a battery cell and to which a current of the battery cell is discharged, the first plate having an area not contacting the battery cell, a second plate disposed between the first plate and the battery cell, the second plate not contacting the battery cell, and a heat transfer part disposed between the second plate and the battery cell and configured to transfer heat generated in the battery cell to the second plate while contacting the battery cell is provided. The second plate contacts the area of the first plate not contacting the battery cell and a portion of the current discharged from the battery cell to the first plate is discharged from the second plate. A heat-radiating system of a cylindrical battery is also provided.