PURPOSE: To prevent the generation of chattering caused by an abnormal vibration and to avoid the reduction of productivity as much as possible in rolling a steel strip.

CONSTITUTION: The vibration generated during rolling is measured by a vibration measuring device provided on a work roll chock 9. A command requiring changing rolling tension is outputted to a tension controller 13 by a vibration controller 14 to which a signal is inputted from the vibration measuring device when the level of vibration exceeds a specific value and, according to the command, the rolling tension is changed and the vibration of a rolling mill is converged. When the vibration is not converged by only the changing of tension, a command requiring changing rolling speed to a speed controller 12 from the vibration controller 14 is output and, according to the command, the rolling speed is changed so as to make the vibration restrained.