Disclosed is a tapping control system capable of performing tapping work with high accuracy and reliability in a manner such that rotation of a tap by means of a digital spindle motor (1) is synchronized with axial drive of the tap by means of a servomotor (2).A digital control circuit (5), used to drive the spindle motor, is supplied with a speed command from position control means (4). The speed command is based on a distributed pulse from an interpolating circuit (3a) for linear interpolation in accordance with the pitch value of a screw to be worked, and a feedback signal indicative of the rotational position of the spindle motor. Also, a servo-circuit (12) for the servomotor is supplied with a distributed pulse from the interpolating circuit. Thus, the two motors are driven synchronously.According to an aspect of the present invention, the tapping work is performed in a fixed cycle such that forward and reverse rotations of the two motors are repeated to reciprocate the tap.According to another aspect, switching means (7) is used to intermittently deliver the distributed pulses and the feedback signal, for selective tapping operation.