The decarbonization of China's central heating (CH) is important for reaching China's carbon peak and carbon neutrality goal. However, unclear CO2 emissions from CH of each city and their disparity hinder the formulation of targeted decarbonization strategies. To solve these issues, this study quantifies the CO2 emissions from CH in 137 cities during the period of 2006–2019 and introduces the Kaya identity and Theil index to investigate the disparity in the per capita CO2 emissions from CH. The results indicate that 1) China's CH CO2 emissions increased to 435.53 MtCO2 in 2019. Residential and public and commercial (P&C) buildings accounted for 74.18% and 25.82%, respectively. 2) The cities with the largest CH CO2 emissions of all (22.58 MtCO2), residential (16.33 MtCO2), and P&C buildings (6.86 MtCO2) were Harbin, Shenyang and Harbin, respectively. 3) The Theil index for all buildings decreased to 0.44 in 2019, and P&C buildings had the largest disparity. 4) The central heating penetration rate was the major positive contributor to the disparity of residential and P&C buildings, contributing more than 40%. In summary, at the city level, this study offers a comprehensive investigation of the CO2 emissions from CH and benefits the formulation of specific decarbonization strategies.