Due to its position as the world's largest energy consumer and carbon emitter, China is facing the great challenge of controlling its rising carbon emissions. As a large country with great disparities in economic development and industrial structure among its regions, it is essential to understand the carbon emission characteristics of regions and industrial sectors in order to formulate effective and targeted policies to achieve domestic carbon emission reduction targets. For this reason, we have conducted a comprehensive analysis in this article of the carbon dioxide (CO2) emissions structure and major responsible sectors for 19 provincial regions of mainland China. Great disparities in direct CO2 emissions and intensities are identified across regions. We show that the direct CO2 intensities in regions are affected by not only the economic development level, but also by the structure of the carbon-intensive sectors and sectoral CO2 emissions intensities. A region-by-region fine-scale breakdown analysis demonstrates that both the direct CO2 emissions and total CO2 emissions are highly concentrated in a minority of sectors: the construction sector is the major contributor to the total CO2 emissions in all regions, followed by the services sectors as a whole. Moreover, the petroleum and chemicals sector, nonmetallic mineral products sector, metal products sector and electricity and steam production sector should also receive more attention, as they are identified as “highly carbon intensive” in most of the regions studied, especially through the close linkage with the construction sector. Based on these results, we discuss and propose policy implications for controlling the rising CO2 emissions in regions of mainland China.