Institute of Energy, Environment and Economy, Tsinghua University (3E), established in 1980, is a university-wide research and education institution supported by Institute of Nuclear and New Energy Technology, Tsinghua University. 3E is among the pioneers in terms of research on energy systems analysis and climate change among Chinese universities. 3E has also been selected as a key national center for Management Science and Engineering research and education by Ministry of Education. 3E is also among the earliest institutions which are entitled to have doctoral and post-doctoral programs in China. Now, the institute has 21 full-time faculties. It received the second prize (two times) and third prize of the National Science and Technology Progress Award, and the first prize of Outstanding Research Achievements of Institutes of Higher Education (Humanities and Social Sciences).