With the development of the economy, the demand for energy in hot summer and cold winter zone in China is increasing very fast while the energy supply is going short. Air conditioning both for cooling and heating accounts for more than 50% of the total electricity used in the residential sector. This paper used eQUEST software to analyze envelope design on energy saving of air conditioner (AC) and the effects of energy saving strategies on AC electric consumption of different orientation rooms in hot summer and cold winter zone in China, which included exterior wall thermal insulation, solar radiation absorptance of exterior wall, area ratio of window to Wall, categories of glazing and kinds of shading system, and two combined strategies. The results indicate that envelope shading and exterior wall thermal insulation are the best strategies to decrease the AC electric consumption which achieved a saving of 11.31 and 11.55%. The optimization of different strategies can decrease the annual electric consumption of AC. by 25.92%, and cooling and heating electric consumption is decreased by 21.08 and 34.77%, respectively, (C) 2008 Elsevier B.V. All rights reserved.