Year 2005 is important because it is the base year for the international carbon reduction commitment and national development plans for China. However, accurate and robust CO2 emission data for 2005 remain limited, particularly for city-level emissions. To address these gaps, we established a uniform city-level CO2 emission inventory for all the 287 prefecture-level cities in China for 2005, combining the High-Resolution Emission Gridded Database (CHRED) 2.0, statistical data and onsite survey. The results showed that Shanghai, Tangshan, Beijing, Tianjin, Jining, Handan, Chongqing, Suzhou, Shijiazhuang and Wuhan were the ten cities with greatest CO2 emissions in 2005, with total CO2 emissions of 205, 184, 145, 126, 116, 103, 96, 93, 90 and 81 Mt, respectively. These cities were either megacities or those dominated by coal, iron or steel production. However, the three cities with the highest CO2 emissions per GDP and CO2 emissions per capita were Jiayuguan, Wuhai and Shizuishan, which were dominated by industry, small- or medium-sized, and exhibited a high demand for heat and cooling. Cluster analysis revealed that industrial energy consumption was the dominant emission source for most cities, except Haikou and Lhasa, for which indirect CO2 emissions were dominant. This study will greatly contribute to the city level CO2 emission inventory and research on China.