Abstract: Transformation from coal-fired boiler to gas-fired boiler is one of the priority projects under the 12th Five-Year Plan in China and it is the most convenient and effective approach to control the coal smoke pollution. From the aspects of economic benefit and environmental benefit, this paper briefly discusses the transformation in Xi'an City and makes a detailed contrastive analysis on main technical parameters of coal-fired boiler and gas-fired boiler in order to expose the common problems in the transformation. The idea of energy performance contracting (EPC) is introduced to this transformation project. Considering the potential problems in the project implementation, a scientific EPC model is chosen - energy-saving benefit payment model. This model can effectively avoid the risks and business conflicts in energy consumption unit and energy service company. Moreover, reasonable transformation suggestions are proposed. The simple economic feasibility analysis shows that the energy performance contracting can help to realize win-win in all parties.