Abstract: The ecological welfare performance (EWP) of China’s provinces from 2010 to 2021 was measured, and the impacts of environmental decentralization and environmental regulation on EWP were empirically examined by employing a two-way fixed effects model. Furthermore, heterogeneity analyses were conducted based on regional differences and varying degrees of environmental decentralization. The results showed that China’s ecological welfare performance exhibited a gentle inverted “U” shape over the study period, with an overall declining trend. The regions were ranked as east > middle > west by performance level. Environmental decentralization had a significant incentive effect on ecological welfare performance. Environmental regulation had a direct effect on the improvement of ecological welfare performance, and their interaction also promoted the improvement of ecological welfare performance. In the regional tests, the impacts of environmental decentralization on the performance of the eastern, central, and western regions were significantly positive, significantly negative, and negatively insignificant respectively; regions with high decentralization and regions with low decentralization promoted and inhibited the improvement of ecological welfare performance respectively, and the negative impact of regions with low decentralization was greater than that of regions with high decentralization. Based on the research results, the following suggestions were put forward: Establish a rational division of fiscal and administrative powers; appropriately adjust the intensity of environmental regulation, coordinate environmental tax rates across provinces according to local conditions; improve the performance evaluation system to prevent local governments from turning a “helping hand” into a “grabbing hand” that harmed people’s well-being.

Key words: environmental decentralization, environmental regulation, ecological welfare performance, fixed effect model