Land use is the most direct way for humans to affect the Earth system and has a significant impact on ecosystem carbon storage. Over the past few decades, China has undergone rapid industrialization and urbanization. A thorough understanding of China's future urbanization process and the corresponding changes in carbon storage will be beneficial for the formulation of future carbon reduction policies in China. This study utilized the InVEST model and land use data under different scenarios to analyze the land use change process and its impact on carbon storage in China's urban clusters in 2020 and 2070, and explored the carbon reduction potential of urban green spaces in the future development of urban clusters. The findings show that under future development scenarios, urban construction will dominate in China's urban clusters, with a relatively small proportion of ecological land. Cropland is the primary source of land transfer in China's urban clusters. Notably, due to policy influence, the transfer of impervious surfaces to cropland compensates for the loss of cropland area. The total carbon storage in China's urban clusters will decrease in the future, with carbon losses from cities far exceeding carbon sequestration. Urban green spaces partially offset 5.31 % of urban carbon emissions, and small and medium-sized cities will be key areas for alleviating carbon emission pressures. Among all development scenarios, the SSP1-26 scenario, which balances urban development with ecological protection, provides an ideal pathway for China's future urban development. This study offers valuable insights for China's dual carbon goals and provides theoretical support for the direction of future urban development.