Abstract: The present invention has an aim of providing a rolling mill and an operation method thereof for remarkably extending a roll life, optimizing a driving source and saving maintenance in the rolling mill. An optimum ratio for the number of driving rotations between driving rolls can be obtained by arranging rolls of predetermined shapes in a plurality of roll stands and adjusting the rolling reduction so as to obtain a required shape, then gripping the material to be formed with a clamping device, drawing the same for a required length without driving any of the rolls and determining the number of rotations or the like of each of the rolls. The driving force between each of driving rolls can be matched and optimized by driving each of the driving rolls at the optimum ratio for the number of driving rotations, which can remarkably extend the roll life, optimize the driving source and save maintenance in the rolling mill.