Abstract: The spatial-temporal differentiation of urban carbon balance pressure and its complex influencing factors are still unclear, especially under the background of rapid urbanization and climate change. Alleviating the pressure of urban carbon balance is of great significance for achieving the goal of "carbon neutrality" and promoting regional low-carbon and green development. To better understand the carbon balance pressure, this study constructed a carbon balance pressure index to analyze the spatial-temporal differentiation in 126 cities at the prefecture level and above in the Yangtze River Economic Belt (YREB). The influencing factors were also explored. The results showed that from 2000 to 2020, the total carbon emissions in the YREB increased rapidly, but the growth rate slowed down after 2010. The total amount of carbon sequestration continued to increase. The overall carbon balance pressure in the YREB increased rapidly, with a slowdown after 2010. Downstream cities had much higher carbon balance pressure than midstream and upstream cities. Midstream cities' carbon balance pressure continued to increase, while upstream cities were still in a state of carbon balance, although there had been an increase in carbon balance pressure. The spatial-temporal differentiation of carbon balance pressure in the YREB was the result of the combined influence of natural and social factors. The factors influencing the carbon balance pressure varied in time and region. Overall, the level of economic development, the scale of the secondary industry, the number of industrial enterprises, and the level of residential consumption had a significant impact on carbon balance pressure. The size of forest land was the most important natural factor, which helped alleviate carbon balance pressure. To alleviate urban carbon balance pressure in the YREB, it was necessary to take action from both emission reduction and carbon sequestration perspectives, by considering the regional characteristics and the influence of various factors.