Abstract: In recent years, carbon emissions have been gradually realized to be a complex issue involving in international economy, trade and politics. This paper analyzed the industrial differences and their motivation factors of carbon emission intensities and researched their contribution rates to changes of carbon emission intensities. Firstly, the paper calculated carbon emission intensities of all industries of China from 1995to 2010using a calculation method and carbon emission coefficients adopted from the IPCC(2006). Results showed that industrial carbon emission plays an important role in carbon emissions intensity''s decline with a declining contribution rate of 73.35%, followed by other service industries with a declining contribution rate of 22.68%; Compared with the low declining contribution rates of agriculture, transportation, business, and construction industries, which were 1.38%, 1.22%, 1.17% and 0.20%, respectively. Secondly, we analyzed industrial differences of carbon emission intensity by Theil index. The result showed that Theil index of carbon emission intensity changed from 0.3927to 0.4889from 1995to 2010, which indicated that differences of carbon emission intensity among various industries tended to be enlarged. The expanding differences had inhibitory effects on the decline of Chinese carbon emission intensity. Then the paper probed carbon emission intensity''s changes by difference factors decomposition model, and finds that technology effect was the driving factor and contributed 104.64% to the decline of Chinese carbon emission intensity from 1995to 2010. On the other hand, structure effect was the inhibition one and contributed -4.64%. Finally, some suggestions such as optimizing industrial structures, speeding up technology research and development and so on were put forward to reduce carbon emission intensity in China.