A proposal has been made to construct a carbon emission reduction potential index, composed of carbon emission efficiency index and equity index, followed by an analysis of the carbon emission reduction potential index of 30 provinces and cities in China (excluding Hong Kong, Macao, Taiwan and Tibet) from 2000 to 2016, as well as an evaluation of emission reduction policies. Based on the comparison between the carbon emission efficiency index and equity index of each province with their average value, a categorization of four regions can be obtained: of high efficiency and high equity (5 provinces or cites), of high efficiency and low equity (8 provinces or cities), of low efficiency and high equity (8 provinces or cities), and of low efficiency and high equity (9 provinces or cities). Beijing, Inner Mongolia and Ningxia Hui Autononmous Region are ranked among the top three provinces in carbon emission reduction potential index, while Hainan, Guangxi and Sichuan are characterized with the lowest carbon emission reduction potential index. Inner Mongolia, Hebei and Anhui have the lowest carbon emission efficiency index, an indication that the three regions have greatest difficulty in reducing carbon emissions. Hunan, Sidchuan and Fujian have the highest carbon emission efficiency index. The regions with the highest carbon emission equity index are Inner Mongolia, Shanghai and Tianjin, while those with the lowest carbon emission equity index are Guangxi, Sichuan and Jiangxi.