This article compiles the energy input-output tables for year 2002 and 2007. Based on the energy input-out tables, we compute the carbon emission volume of China and by sector. The article also analyzes the source and change of the emission volume, based on structural decomposition analysis. The article finds that there are five factors affect the carbon dioxide. Among which the change of emission intensity, domestic need are the main reason of the decrease of emission, while production technology, trading structure and scale effect increase the emission volume. We also find that although the direct emission intensity decrease during the study period, the complete emission intensity increase by an annual rate of 3.8%, which reflect the result of energy policy is not equal in different sectors. We cannot deny the technologic and economic linkages between sectors when establish an energy policy.