Abstract: In this paper, based on the introduced model predictive control (MPC) technology, the scheme of MPC-based coordinated control system (CCS) and main steam temperature control system is proposed and applied on two ultra-supercritical coal fired power generation units. The comparison between the results of MPC- and PID-based controls shows that the MPC controller can increase the load control accuracy, load variation rate as well as the unit maximum generation, and lower the control error of main steam pressure. The MPC system has been successfully in operation for ten months, which makes the power grid evaluation scores of the two units to be improved considerably, that is, the K_p values have been increased from 1.5 to 2.8 and 3.5 respectively; the rank of the power plant has been increased from medium level to the second (out of 47 power plants) in the local power grid.