The operation performance of building cooling, heating and power (BCHP) system is dependent on the seasonal atmospheric conditions. This paper presents the environmental impact models of separation production (SP) system and BCHP system respectively. Three most important energy-related environmental issues, global warming, acid precipitation and stratospheric ozone depletion, are considered to evaluate the environmental impact of BCHP system for a commercial building located in five climate zones, China. Because the global emissions of BCHP system are related to the central power plant that provides the additional electricity to building, the environmental impacts by coal-fired and gas-fired power plants are compared and discussed. The results indicate that the emission reduction potential of BCHP system over SP system in hot summer zone and mild zone is larger than in severe cold zone when the coal-fired power plant is used. Contrarily, BCHP system in severe cold zone reduces more emissions than in hot summer zone when the gas-fired power plant provides the additional electricity. (C) 2010 Elsevier Ltd. All rights reserved.