Abstract: A temperature controlling method for heating, with a heating furnace having at least one heating zone provided with a controllable heating means, materials charged into the heating furnace such that an aimed temperature of the material is reached by the time when the materials leave the heating furnace. The characteristic feature of the invention resides in that the instructions for changing the operating condition of the heating furnace in response to a change in the rolling condition of the rolling line connected to the heating furnace is treated as a change in the period of stay of the material in the heating furnace. In the controlling system in accordance with the invention, determination of the material temperature rise pattern in response to the change in the staying period of the material in the furnace is made to minimize the supply of fuel to the heating means, and the set temperature of each heating zone is calculated from the thus determined temperature rise pattern.