PURPOSE: To improve mechanically a rolling condition and to obtain a load balance of motors by controlling the position of an auxiliary roll provided to the inlet or outlet side of a rolling mill when the load distribution between motors for separately driving a pair of rolls is unbalanced.

CONSTITUTION: In rolling a strip by driving a pair of rolls RA, RB of a mill with the aids of respectively independent motors MA, MB, an auxiliary roll 1 for controlling the height of the strip is provided to the inlet or outlet side of the mill. When an unbalance between the armature currents IA, IB of the motors MA, MB is cuased by rolling, a load balancing circuit LB outputs a position correcting signal in accordance with the amount of unbalance to a position controlling device 3, which controls the height of roll 1 with the aid of a hydraulic cylinder 2 and changes a strip biting angle with respect to the rolls RA, RB. Further, supplementary rolls 11W13 are provided for enlarging the controlling range. In this way, a rolling condition which causes load unbalance is mechanically improved.