Electric power companies pay attention to the load following capability and economical operation of a thermal power plant. However, conventional PID controllers embedded in DCSs cannot always provide the optimum solution for such subjects. To cope with these problems, we discuss a model predictive control(MPC) system to tune PID controller parameters. Prior to study of the advanced control system, we develop a nonlinear system model considering the characteristics of power plant dynamics. This article applying feedback linearization technique to predictive PID control of superheater steam pressure and power output of a boiler-turbine generation unit. The simulation results show the improvement can be achieved in control with predictive PID control system, and these improvements in control can be maintained for large changes in operating conditions.