Abstract: An ink pump control system driven by a stepping motor comprising a pulse generating section for generating stepping motor driving pulses, an arithmetic section for obtaining a time difference .DELTA.t=T.sub.2 -T.sub.1 between the time T.sub.2 and time T.sub.1 required to cause the stepping motor to rotate in angular movements at a hypothetical revolution speed r.sub.2 required for feeding ink and a predetermined revolution speed r.sub.1 based on printing speed data and printing element ratio data, a predetermined pulse output section for outputting pulses that cause the stepping motor to rotate intermittently at high speed based on the pulses generated by the pulse generating section and the time difference obtained in the arithmetic section, and an excitation signal output section for outputting an exciting signal to cause the stepping motor to be actuated by a motor driver.