PURPOSE: To provide a vertical roll driving device by which a difference in speed between a rolling stock to be rolled and the peripheral speed of the vertical roll can be eliminated at the time of the bite of the rolling stock by surely rotating the vertical roll as necessary in a universal rolling mill.

CONSTITUTION: A hydraulic motor 12 is arranged in the central part inside a shaft part 11 supporting the vertical roll 3 of a vertical roll chock 7, and an internal gear 9 is rotatably provided as one body on the inner peripheral surface of the vertical roll 3. The vertical roll 3 is allowed to rotate by a driving gear 13 rotated and driven by the hydraulic motor 12 through reduction gears 14 to 16 engaging in the internal gear 9.