Energy-related CO2 emission projections of China up to 2030 are given. CO2 mitigation potential and technology options in main fields of energy conservation and energy substitution are analyzed. CO2 reduction costs of main mitigation technologies are estimated and the multi-criteria approach is used for assessment of priority technologies. The results of this study show (1) Given population expansion and high GDP growth, energy-related CO2 emissions will increase in China. (2) There exists a large energy conservation potential in China. (3) Adjustment of industry structure and increase of shares of products with high added value have and will play a very important role in reducing energy intensify of GDP. (4) Energy conservation and substitution of coal by natural gas, nuclear power, hydropower and renewable energy will be the key technological measures in a long-term strategy to reduce GHG emission. (5) Identification and implementation of GHG mitigation technologies is consistent with China’s targets of sustainable development and environmental protection (6) Energy efficiency improvement is a "no-regret" option for CO2 reduction, whereas an incremental cost is needed to develop hydropower and renewable energy.