A gantry rotation control device for a computed tomography scanning apparatus The device includes a radiation dose determination unit for determining radiation doses of the X-rays that will be emitted to each site of the target object to be scanned, a minimum velocity determination unit for determining a minimum rotation velocity of the gantry according to a maximum radiation dose in the determined radiation doses, a maximum velocity determination unit for determining a maximum rotation velocity of the gantry according to the determined minimum rotation velocity, a rotation velocity determination unit for determining a rotation velocity of the gantry at any time during scanning of the target object according to the determined minimum rotation velocity and maximum rotation velocity, and a gantry rotation control unit for controlling the gantry to scan the target object while rotating according to the determined rotation velocity when the target object is to be scanned.