China faces growing environmental problems as rapid economic growth comes at the cost of excessive resource consumption. Sustainable development can only be realized by reducing energy intensity. Although some general factors that influence energy intensity have been described, less information is available to compare energy intensity in different regions. Here we use existing literature to assess the effects of three internal factors (economic structure, energy consumption structure, and technological progress) on energy intensity in three regions of China. We use panel data from 2000 to 2009 and find that the effects of each factor differ in each region. We further differentiate these effects by decomposing technological progress into three parts using the DEA-Malmquist approach. We find three components of technological change have completely different effects in each region. Furthermore, these findings are applied to propose relevant suggestions to reduce energy intensity in different regions of China.