Abstract: The measurement of high-quality economic development level in the Yangtze River Economic Belt, along with an examination of its distribution dynamics, transfer characteristics, regional disparities, spatial agglomeration and obstacle factors, holds significant practical implications for establishing exemplary models of regional economic development and constructing a pilot demonstration zone for high-quality economic development in China. Based on fundamental data from 102 cities in the Yangtze River Economic Belt spanning from 2011 to 2020, this study constructs an evaluation index system for high-quality economic development. The level of high-quality economic development is measured through a comprehensive utilization of vertical and horizontal scatter degree method, fixed base efficiency coefficient method, and linear weighting method. Building upon this foundation, systematic analysis is conducted employing kernel density estimation, Markov chain estimation, Dagum Gini coefficient, Arcgis mapping technique, spatial Moran’s index, Moran scatter plot as well as obstacle factor diagnosis. The findings are as follows: (1) The level of high-quality economic development in the Yangtze River Economic Belt has steadily improved during the study period, with significant variations observed among provinces and cities. The regional development gap underwent an initial expansion followed by a subsequent narrowing, leading to a transformation from a pattern of multi-level differentiated gradient development to one of polarization, while also witnessing the emergence of a trend towards balanced development. (2)There is a high probability that each city will maintain its current level of development, confirming the phenomenon of solidification at high-level cities. (3)The regional gap primarily stems from inter-regional disparities and has shown a decreasing trend over the years. (4)High-quality development exhibits both high agglomeration and low agglomeration spatial characteristics, with significant radiation effects from higher-level cities. (5)The per capita utilization of foreign capital, residents' living standards, the level of marketization, and the rationalization of industrial structure are key determinants influencing the high-quality economic development in the Yangtze River Economic Belt. Additionally, factors such as unemployment rate, per capita participation in pension insurance, and energy efficiency also pose significant challenges to enhancing the level of high-quality economic development in certain provinces and cities.