Abstract: The carbon sequestration service can mitigate climate change by capturing and absorbing atmospheric CO₂. The carbon emission and the pressure to reduce emission is increasing with the development of regional economy and society. It has an important theoretical and practical significance for formulating or optimizing emission reduction targets and guiding regional sustainable development to study the temporal-spatial dynamics of the relationship between supply and demand of carbon sequestration service. This paper took the Yangtze River Delta region as an example, which clarified the connotation and measurement method of supply and demand of carbon sequestration. This paper quantified the demand under different carbon emission reduction targets and estimated the supply, and further estimated the supply-demand relationship between the Yangtze River Delta as a whole and between provinces. The results showed that, the relationship between supply and demand tended to be tight during the 15-year period, especially in the central and eastern regions, where the supply-demand ratio has dropped from 50.86% to 16.36% under not considering the target of carbon emission reduction; The carbon supply-demand ratio in 2015 was 40.17% under the target of 30% emission reduction and it was 31.59% under the target of 30% emission reduction in YRD, where the deficit area was mainly distributed in urban centers. The reason for tension between supply and demand was the increase of carbon emission, especially the carbon emissions in industrial. Therefore, the YDR should increase the space for carbon sinks and speed up the industrial transformation in the deficit area to ease the contradiction between the supply and demand. At the same time, it must establish regional compensation mechanisms and policies on carbon sequestration services at the provincial and inter-provincial levels to promote the integrated development.