Abstract:Research on thermal cycles and integrated energy systems is one of the important subjects for energy and environmental science, which is also emphasized in the National Mid-to-Long Term Plan for S&T. Based on the identification of the role of thermal cycles and integrated energy systems, this report points out new tendency for sustainable development, including cascade utilization of energy, new approaches of energy release, mid- and low- temperature energy utilization, multi-energy integration system, principles of greenhouse gas control technologies. The key pointed out here aims to opening up the promising prospects for thermal cycles and integrated energy systems to utilize energy effectively and resolve energy and environmental problems simultaneously.