Abstract: Based on provincial panel data from 2003 to 2016, the relationship between urbanization and carbon emission in China was studied by constructing a threshold regression model. According to the threshold of real GDP per capita, 30 provinces are divided into four groups of lowest-income, lower-income, higher-income and highest-income. The results show that the relationship between urbanization and carbon emissions of four groups is in line with the Kuznets curve of inverted U shape. Among them, the inflection point corresponds to an urbanization level of 35.55% for the lowest-income group and to 44.64% for the lower-income group. For the highest-income group (more than RMB 29 040 yuan), the relationship between economic growth and carbon emission conforms to the Kuznets curve, and it is in the downward phase of an inverted U curve. In addition, the process of industrialization and investment of energy-saving and emission reduction are still promoting carbon emissions. Therefore, China’s energy conservation and emission reduction strategy should follow the law of economic and social development, considering the varying effects of the economic development level, development speed, and degree of urbanization of different provinces on carbon emissions, taking into account the dual goals of economic development and environmental regulation.