The development of urbanization is accelerating in China, and there are great pressures and opportunities in cities to reduce carbon emissions. An emissions inventory is a basic requirement for analyzing emissions of greenhouse gases (GHGs), their potential reduction and to realize low-carbon development of cities. This study describes a method to establish a GHGs emissions inventory in Chinese cities for 6 emission sources including industrial energy consumption, transportation, household energy consumption, commercial energy consumption, industrial processes and waste. Nanjing city was selected as a representative case to analyze the characteristics of carbon emissions in Chinese cities. The results show that carbon emissions in Nanjing have increased nearly 50% during the last decade. The three largest GHGs contributors were industrial energy consumption, industrial processes and transportation, which contributed 37-44%, 35-40% and 6-10%, respectively, to the total GHGs emissions. Per GDP carbon emissions decreased by 55% from 2002 to 2009, and the per capita and per GDP carbon emissions were comparable or even lower than the world average levels. These results have important policy implications for Chinese cities to control their carbon emissions.