Urban carbon budget estimation is one of the key topics of the study on global climate change. Carrying out the carbon budget estimation of cities not only helps build the theoretical framework of regional carbon balance analysis,but also has great significance for the compilation of regional greenhouse gas inventory and the choice of low-carbon development pattern.Zhengzhou City was chosen as an example and the carbon emissions in the year 2030 was predicted by adopting the liner regression method and the least squre method.The low-carbon urban development policy suggestions were put forward on the basis of urban carbon budget study.The main conclusion are as follows.(1)The carbon emission and the carbon sink were not matching obviously.The carbon emission and its growth rate were significantly more than the carbon sink. Among them,the energy activities and the crops were the main source of carbon emission and carbon sink, respectively,and both of which accounted for more than 80%of the emission/sink.(2)The carbon intensity of Zhengzhou presented the decline trend,suggesting that carbon intensity improved significantly along with the implementation of policies of the energy conservation and emission reduction and the transformation of the regional pattern of development.However,the economic growth and the carbon emission were in the weak decoupling state and the development of economic still relied on the consumption of energy and the emission of carbon.(3)According to the prediction we find that there will be a substantial increase of the carbon emission in 2030 compared with the emissions of 2012,but the carbon efficiency will enhance gradually and the expected emission growth rate will decline.