Abstract: Green development is one of the core elements of regional high-quality development. An analysis of the spatial-temporal pattern evolution and its driving mechanism can help provide a scientific basis for policy formulation. This paper constructs the evaluation index system of green development level of Yangtze River Economic Belt from six dimensions: green economy, green production, green environment, green ecology, green innovation and green living. The panel entropy-Critic method, kernel density estimation, spatial autocorrelation analysis and spatial Durbin model are used to explore the green development level of 108 prefecture-level cities in Yangtze River Economic Belt from 2010 to 2019. The results show that (1) the overall green development level of the Yangtze River Economic Belt shows an increasing trend, with relatively significant spatial divergence characteristics and gradually expanding overall differences; (2) the overall green development level of the Yangtze River Economic Belt has spatial dependence and spatial spillover, and has relatively obvious spatial club convergence characteristics, with the H-H agglomeration area. The H-H agglomeration is mainly located in the downstream region of Jiangsu, Zhejiang and Shanghai, while the L-L agglomeration is scattered in Yunnan, Guizhou and Sichuan, and the polarization phenomenon within the belt is quite obvious; (3) economic development, environmental regulation, scientific and technological progress, industrial structure optimization, government support, human resources and natural resources conditions obviously have positive effects on green development within and between regions.