In a modern power plant, the economy of boiler-turbine system has recently aroused too much concern, while load tracking is no longer the only significant task for control and optimization purpose. Traditionally, the economy of the boiler-turbine system has been handled in a multi-layer hierarchical architecture, which neglects the economy of the dynamic tracking process. In this paper, an economic model predictive controller is developed. It directly utilizes the economic index of boiler-turbine system as the cost function and realizes the economic optimization as well as the dynamic tracking. A stable Sontag controller and corresponding region are designed to ensure the stability of the closed-loop system. Then, the optimization problem of this economic model predictive control is solved on-line using Laguerre functions. Simulations are given to show the effectiveness of the proposed controller. (C) 2018 Elsevier Ltd. All rights reserved.