According to comparable price energy input-output table of China during 20002007, this paper analyzes the changing trends of the six departments of completely energy consumption coefficient, then uses factor decomposition method to decompose energy intensity into three determinants such as direct energy intensity change, product technical change and the final demand structure change, and analyzes the influence of different factors on the energy consumption intensity change and changing characteristics of different factors in various sectors. The results show that the completely consumption coefficient of industry on coal and petroleum totally demonstrates declining trend, that the total energy consumption intensity quantity of coal and petroleum shows negative change mainly because of direct energy consumption intensity change, that energy consumption intensity quantity of gas and power demonstrates positive change mainly because of final demand structure change and product technical change respectively, and that product technical change is not helpful to energy consumption intensity decline of agriculture, industry, architecture industry, transportation, storage industry, postal industry and other non-material sectors. By and large, national macro-adjustment policy and energy conservation measures have played active role, however, energy consumption intensity shows rebound trend, and thus, China should still need to implement energy conservation and emission reduction measures.