The study summarizes experience in the compilation and application of city GHG inventories, discussing 1) the purpose and significance of city GHG inventories; 2) support systems for city GHG inventories, 3) content of city GHG inventories, 4) activity data collection, 5) tools for calculating emissions, and two problems based on existing experiences – calculation of transport emissions and emissions calculation at the county level. In application, this study considers the direction and need of domestic low-carbon development, focusing on four main areas 1) goal setting, 2) performance tracking, 3) low-carbon development roadmaps, and 4) emissions trading system (ETS) rules setting.