China has made great achievements in economic and social development since 1980s. With the continuous growth of economy and population, higher energy intensity and special energy structure will cause the continuous growth of primary energy consumption and CO2 emission in the next 20-30 years in China. Based on the projection of population that the UN offered and GDP growth that Energy Information Administration provided, energy consumption in next 20 years in China is forecasted in this paper. Coal-based energy consumption structure decided the inevitable growth of CO2 emission in China in the future. According to historical data of 4 indicators related with CO2 emission, more than 50 countries are classified to 4 sorts through K-means cluster analysis, which offers reference for scenario analysis of CO2 emission in China in the future. In high-emission and low-emission scenario, CO2 emission is forecasted respectively. Finally energy strategy option from Chinese government is discussed. China is actively adjusting the economic and energy structure, comprehensively promoting energy conservation, controlling environmental pollutants emission effectively, and promoting the coordinated development of energy and environment.