Abstract: Abstract：Based on the panel data of 110 cities in Yangtze River Economic Belt from 2011 to 2016, this paper explored the effect of environmental regulation on the cities’ efficiency of industrial green development by the spatial Durbin model from their inner theoretical mechanism. The results suggested several findings. The impact of environmental regulation on the cities’ efficiency took on a “U-shaped” trend, which first inhibited and then promoted. The green guidance effect needed to go through a certain period of time before appearing. Environmental regulation’s promoting effect presented significant regional heterogeneity, showing a gradient decreasing pattern in the downstream, upstream and middle reaches, and its cost constraint effect always dominated the middle reaches. Environmental regulation led to the diffusion and transfer of polluting industries among cities, especially in the middle and lower reaches. Environmental governance in the upper reaches was weak enough to affect the decision-making of enterprise migration. To further enhance the cities’ industrial green production capacity in Yangtze River Economic Belt, it is necessary to strengthen the coordinated treatment of industrial pollution, improve the accuracy of environmental policy, and accelerate the research and application of green technology innovation.