Abstract: A 3 input/3 output control system of a Pilot paper machine head box has been studied with decoupling and pole assignment solved through linear state feedback.Based on Wolovichs Synthesis a computer subroutine has been worked out and special attention paid to the conventional controller (DDZ-Ⅱ) implementation of this multivariable control system.Some practical simplifying methods have been also suggested in this paper.Series of experiment results show that the resultant control system works quite well.