Recommended values of life cycle carbon dioxide emission (LCE) for China were put forward by statistical study on different power generation forms of LCE. Current situation of total greenhouse gas (GHG) emission from power sector was calculated based on the analysis of current energy structure development of power sector in China. Three scenarios were made to predict power mitigation in the future based on the proportion requirements on generated energy of different power forms prediction in power sector. In baseline scenario, the energy structure in power sector were set as the situation in 2012 to establish different shares of each power forms and the low LCE system was used in the added coal fired generation. Results show that the annual average LCE has not been changed, and the mitigation target could hardly be realized with meeting the economy development. In restricted scenario, the shares of each power form are adjusted according to the policy goals, and the LCE of coal power is reduced year by year according to the technological development. The effect of mitigation is obvious and the total LCE is largely reduced, however, to reach the GHG emission peak in 2030 is still hard. In optimistic scenario, larger share of non fossil power is set and the LCE of coal power is further reduced. GHG emission in 2030 will stay stability, making it possible to reach the targets. In the evaluation years from 2013 to 2030, GHG reduction is 6.66, 25.56 and 29.70 billion tons by the three scenarios, respectively, compared with the results of maintaining the development of average technological level in 2012.