In order to research energy efficiency design of public buildings, the large and medium scale of typical department stores in Chongqing are chosen as objects and twelve stores are investigated about their operational energy. Based on the investigation results, the composition and features of operational energy are analyzed ; it is shown that the short of effective measures in respect of architectural design leads to the high power consumption in department stores. According to the local climate and environment characteristics, this paper puts forward concept of holistic energy efficiency and offers series of design strategies which lead to energy conservation in stores,such asefficiency.regardingclimate as resources and applying appropriate technology to attain energy efficiency.