Abstract: The spatial differences between regional carbon emission efficiency and high-quality development are significantt is to dynamically grasp the evolution of the spatial and temporal patterns and the coupling development trend of the two to promote the balanced development of the Yangtze River Delta urban agglomeration. Taking 26 prefecture-level cities as the research objects, this paper construct the index system and coupling degree model to measure carbon emission efficiency and high-quality developmententropy weight method, SBM model and Tobit panel model to reveal the macro pattern of carbon emission efficiency and high-quality developmentfrom 2000 to 2020 he spatial and temporal differences of their coupling development and the driving factors. The results as follows: (1) The inter-annual changes in carbon emission efficiency and high quality development show a synchronized upward trend fluctuation; he former gradually show “North-South” differences in macro patterns, while the latter’s “East-West” differences gradually becme. (2) The coupling degree and coupling coordination degree of carbon emission efficiency and high-quality development in the period of primary coordination and above, with an overall upward trendhe gap between the two in different provinces and cities haexperienced a change of first narrowing and then widening. The macro pattern of the two differsignificantly, but both show the characteristics of contraction of the high-value area to the core cities and the periphery, and the “southeast-northwest” difference is obvious. (3) Economic base, government intervention, urbanization rate and industrial structure contribute to the degree of coupling coordination, while carbon emission intensity haa negative constraining effect on it. Finally, suggestions put forward in terms of promoting synergy between the two, strengthening inter-regional interaction and differentiated development paths.