Based on autoregressive distributed lag model to analyze the main factors 1980-2007 China's carbon intensity. The results showed that carbon intensity per capita GDP, energy efficiency, and long-run equilibrium relationship between the proportion of industrial added value. Energy efficiency improvements of carbon intensity decreased, the proportion of industrial added value increased carbon intensity rises. The presence of an inverted U-shaped relationship between per capita GDP and carbon intensity. Chinese carbon intensity in the early 1990s, reached a turning point. However, due to the recent decline in energy efficiency and the increased proportion of industry, China's carbon intensity has rebounded.