A control system of coal pulverizer associated with a rotary classifier, applicable to a pulverized coal burning boiler or the like, includes a function generating section, a computing section, and a rotational speed controlling section. The function generating section receives a signal representing a coal feed rate and outputs signals representing a preset proper range of a current to be fed to the motor of the coal pulverizer for such coal feed rate. The computing section is responsive to a signal representing the current motor current and the signals produced by the function generating section to output a command signal which will maintain the speed of the rotary classifier when the motor current represented by the motor current signal is within the proper range, and to output a command signal which will decrease or increase the speed of the rotary classifier, respectively, in the case where the same motor current has increased or decreased beyond the proper range. The rotational speed controller receives the command signal and regulates the speed of the rotary classifier on the basis of the command signal.