This study explores the empirical relationship between city-level urban forms and CO2 emissions in 104 Chinese prefectural-level cities. Although the analytical focus is on polycentric urban forms, the analysis has also accounted for population size and land use compactness. CO2 emissions data are aggregated from the Fossil Fuel Data Assimilation System (FFDASv2) data portal. The analysis identifies substantial economies of scale in CO2 with respect to total population. Further, despite a substantial wealth effect on CO2 emissions, cities with more centralized and compact urban forms are associated with lesser emissions, ceteris paribus. Whereas existing analyses of CO2 emissions in Chinese cities have often been limited to a handful of provincial capitals, the analysis covers a larger sample of cities. The paper concludes with spatial planning policy implications.