Abstract: This paper is concerned with the disscussion of observer compensator control schemes of the process with time delay. The first control scheme discussed has the following advantages over that based on the Smith predictor: easy to install and robust for the changing of process model parameters. The second one, analogous to feedforward control, has the capability of fully overcoming the effect due to measurable disturbances. The last control scheme presented in this paper, having the advantages of the previous two schemes, is characterized by good stability and adaptive nature and digital simulation studies show that it can also be applied to time-variant and nonlinear processes.