The dot impact printer of the invention sets an optimum printing speed based on various factors, such as kanji or alphanumeric characters, and to set an optimum brake pulse and an optimum energizing energy corresponding to the set optimum printing speed. The printing mode is determined through a series of logic steps and optimum settings for the printing actions is selected according to the mode identified. Thus, in the invention, based on the print contents, a printing speed, an energizing period of time for the first dot, an energizing period of time for the following dots, a brake pulse width, a period of time till the generation of brake pulses and delay time, are changed.