Promoting regional coordinated development is of great significance to the realization of Chinese-style modernization.However,the phenomenon of pollution transfer resulting from environmental regulation intensity differences may affect the process of regional coordinated development.Therefore,using provincial panel data from 2001 to 2019,this paper measures the level of regional coordinated development in each prov-ince based on an improved local coordination model.We also explore the impact of environmental regulation intensity differences on regional coordinated development.The results show that the environmental regulation intensity differences significantly inhibit regional coordinated development.Heterogeneity analysis reveals that the inhibitory effect of environmental regulation intensity differences on regional coordinated development was influenced by the marketization level and geographical location.Mechanism test suggests that environmental regulation intensity differences may hinder technological innovation and the rationalization of industrial struc-ture,thereby impeding regional coordinated development.Finally,we put forward the policy recommenda-tions:the appropriate centralization of environmental authority and the accelerated construction the unified na-tional market.The paper provides valuable references for promoting regional coordinated development,impro-ving high-quality development and realizing Chinese-style modernization.