Steam parameters control problem in power plants with coal fired boilers is one of the most challenging problems. The steam parameters are extreme at the boiler outlet. The large time constants and nonlinearities are involved in the process model. In this paper, it was shown that the feedback linearization method could be applied to synthesise control system for this process. The derivation of the linearizing transformation is not an easy task. It requires symbolic solutions for ordinary differential equations. The proposed method was compared with PI and proportional state feedback control algorithms. Simulation experiments were carried out in different points of operation, with different heat distribution and in presence of unmodelled dynamics.