Mid- and long-term energy requirements and greenhouse gas emission scenarios for China were presented by using the Integrated Policy Assessment Model of China. Technologies are the key component to reach a low carbon future. Technologies are identified with the scenario analysis. In order to realize the low carbon future, a technology roadmap was presented to reach the emission reduction up to 2050 in China. Twenty-eight key technologies are given in the paper for the technology roadmap, presenting learning curves. With full adoption of these key technologies, we do see ample opportunities for China to make the emission stable after 2020, without a large increase, and even start to have a deep reduction after 2030.