Abstract: Abstract：Green development is crucial for the high-quality development of resource-based cities. This study proposed an evaluation system for green development efficiency（GDE）, using the Theil index, panel quantile regression model, Geodetector to measure GDE in the Yangtze River Economic Belt（YREB）from 2001 to 2021. The spatiotemporal heterogeneity characteristics and associated driving factors as well as their interaction effect were analyzed. We concluded that:(1) The 38 resource-based cities in the YREB all exhibited an M-shaped trend; The upstream resource cities' GDE was marginally higher than that of the middle and downstream resource cities; The growing resource cities' GDE was lower than that of the other three types of cities; (2) The GDE of resource-based cities in YREB tended to have the normal distribution in quantity, resulting in a severe imbalance. The primary cause for the disparity in GDE was the alteration of upstream resource-based cities; (3) The degree of openness to the outside world, the amount of scientific and technological inputs, population density, and the amount of educational inputs contributed largely to the increasing GDE. We concluded that the two driving mechanisms were the “population-economic outward orientation-education” and “population-economic outward orientation-education-technology”, and the two restricting mechanisms were the “economy-transportation-pollution” and “economy-transportation-resources”; (4) Population density had the best interaction effect with the degree of opening to the outside world and the intensity of scientific and technological input. We should focus on the coordinated development of multi-factors, and strengthen the synergistic inter-regional governance to provide a scientific basis for improving the GDE of various resource-based cities in the YREB.