China faces rigorous energy and environment problems，so it is necessary to conserve energy and reduce emission，promote energy efficiency，reduce emissions of pollutants，and step up environmental protection. All of these efforts are necessary to achieve the goal of comprehensive construction well-off society，ensure energy security and protect environment. In the section one，we simply look around the status and trend of world’s energy conservation & emission reduction. Moreover，we also survey the actions of developed countries in energy conservation & emission reduction as reference. In the section two，we focus on the status and challenges of China’s energy conservation & emission reduction. In the section three，we analyze the practice and successful experiences of international developed countries，and interpret the related energy conservation & emission reduction policies in China. Consequently，we give some suggestions to current and future working focus，and further measures. Finally，we take the cases of representative enterprises in several energy-consuming industries，analyzing their measures，effects and experiences in the practice of energy conservation & emission reduction.