PURPOSE: To prevent upper and lower work rolls from producing surface roughening by monitoring roll ends and spraying a roll lubricant on the roll ends when roll kissing is pre-estimated in the control method of different peripheral-speed rolling of a strip by a cold mill.

CONSTITUTION: When decided that roll kissing will generate at the ends of work rolls 2, 3 in the different speed rolling of a strip 1, a header 8 for spraying a lubricant, a partition board 10 and a lubricant collecting pan 16 are positioned in accordance with the width of strip 1. At that time, an arithmetic unit 15 actuates a device 14 for positioning the header 8 as well as outputs a signal to a control unit 13 of lubricant pump 11, when the sheet width of strip 1 is inputted, to rationalize the spraying rate of lubricant to the roll ends. In this way, the ends of work rolls are prevented from producing surface roughening in different speed rolling.