A drive control method for stepping motors as used in connection with controlling throttle valves for internal combustion engines. A computer controls actuation of the throttle valve in accordance with engine operating conditions and the like, as well as the amount of fuel being injected to the engine. The method includes steps for increasing the response speed of the stepping motor without detracting from its resolution. Instead of predetermined rotation angles, the stepping motor repeatedly actuates in a time period which is determined as the sum of its stationary time after one rotation step, and its stationary time after the following one rotation step. This enables obtaining substantially smaller and hence faster angular displacements of the stepping motor than use of predetermined unit rotation angles.