China is the world's largest energy consumer and CO<sub>2</sub> emitter. Cities contribute 85 % of the total CO<sub>2</sub> emissions in China and thus are considered the key areas for implementing policies designed for climate change adaption and CO<sub>2</sub> emission mitigation. However, understanding the CO<sub>2</sub> emission status of Chinese cities remains a challenge, mainly owing to the lack of systematic statistics and poor data quality. This study presents a method for constructing a CO<sub>2</sub> emissions inventory for Chinese cities in terms of the definition provided by the IPCC territorial emission accounting approach. We apply this method to compile CO<sub>2</sub> emissions inventories for 20 Chinese cities. Each inventory covers 47 socioeconomic sectors, 20 energy types and 9 primary industry products. We find that cities are large emissions sources because of their intensive industrial activities, such as electricity generation, production for cement and other construction materials. Additionally, coal and its related products are the primary energy source to power Chinese cities, providing an average of 70 % of the total CO<sub>2</sub> emissions. Understanding the emissions sources in Chinese cities using a concrete and consistent methodology is the basis for implementing any climate policy and goal.