In a speed change control method for setting the gearshift position of an automatic transmission for vehicles with a plurality of gearshift positions, to a position selected on the basis of vehicle speed and engine load, in accordance with a preset shift pattern for a first control mode, one of the gearshift positions is selected by fuzzy inference in accordance with at least one of parameter values which represent operating conditions of the vehicle, parameter values which represent driver's driving intention, and parameter values which represent road conditions, and the gearshift position of the automatic transmission is set to the position selected by the fuzzy inference only if the gearshift position selected by the fuzzy inference provides a lower speed than that provided by the gearshift position selected in accordance with the shift pattern for the first control mode. Preferably, a plurality of control modes including the first control mode are provided, one of the control modes is selected by the fuzzy inference in accordance with at least the degree of winding and gradient of a road on which the vehicle is traveling, and a gearshift position to be set is selected in accordance with the selected control mode.