Abstract: A method for controlling the temperature of the printing head of an impact printer, capable of selectively changing the printing mode of the impact printer between the bidirection printing mode in which the printing head performs printing operation while it is moved in either of the reciprocating directions, the single direction printing mode in which the printing head performs printing operation while it is moved in one of the reciprocating directions and the idle reciprocation mode in which the printing head is merely reciprocated without performing printing operation, according to output signals of a low-level comparator which compares the measured temperature of the printing head with a low-level reference value and gives an alarm signal when the measured temperature is higher than the low-level reference value and a high-level comparator which compares the measured temperature with a high-level reference value and gives an alarm signal when the measured temperature is higher than the high-level reference