PURPOSE: To minimize the generation of an abnormal rolling state and to shorten the time of generation of the abnormal rolling state even if the abnormality is generated.

CONSTITUTION: The parameter affecting to the carrying volume of rolled stock 1 carried out from the rolling mill 10 in an upper stream is measured. Then, as for the parameter, the deviation of the schedule value and the actual value by comparing the schedule value preliminarily decided with the actual result value obtained by measuring. Further, as for the rolling mill 15 of down stream, the rolling state of a case that the relative rolling speed against the upper stream rolling mill 10 is changed and a case that the relative rolling speed of present is kept is inferenced based on the deviation, the most suitable state for the inferenced rolling state is selected among the assumed each relative rolling speed. Thus, the rolling speed of the rolling mill 15 in the down stream is controlled so as to be the selected relative rolling speed.