Existing large-scale public building energy saving renovation is the inherent requirement of sustainable development, it has been proved that implementing the energy performance contracting mode in the Existing large public buildings energy-saving is an effective way both at home and abroad. EPC mode has obvious characteristics for the ESCO and the customers, it can meet the basic requirements of large public buildings energy-saving, such as the width of funding sources, program specifi cation, advanced technology, information fl ow and management level higher, etc. Under the condition of market economy, it also provides a broad platform for the ESCO implements building energy saving transformation, which is conducive to the realization of the win-win cooperation between the parties, and to promote the healthy development of the existing large public building energy saving reconstruction.