Recently, register controllers which automatically control color to color registration in gravure presses are very popular in printing industry, but the controlling ability is regarded as insufficient. Therefore, we have developed the most efficient register controller which automatically calculates optimum correction values depending upon the construction of a printing press and printing conditions, then corrects the register error rapidly thereby reducing spoilage to a minimum. To make the most efficient register controller, first of all, we made the calculation model of a printing press and became to be able to simulate the phenomenon of a register error by a computer. Then we decided to control in PD control method and could obtain the optimum gains in PD control through simulating the phenomenon of a register error by changing printing conditions such as the pass length between the printing units, the compensator roller displacement velocity, the printing speed, the tension of the web and the radius of the gravure cylinder, affecting the register control. Finally, we have developed the controller that always controls registration in response to the construction of the printing press and printing conditions.