Abstract:Green technology innovation is the core driving force for the high-quality development of regional integration in the Yangtze River Delta, and the free flow of innovative elements represented by green technology across cities is the due meaning of the construction of ecological green integration in the Yangtze River Delta. Based on the inter-city green patent transfer data from 2001 to 2020, this study analyzed the characteristics of the spatial evolution of green technology diffusion in the Yangtze River Delta, and discussed the development degree of ecological green integration in the area from the three levels of overall development, green technology supply, and green technology sales. This study found that the core area of the Yangtze River Delta urban agglomeration, consisting of the Shanghai-Suzhou-Wuxi-ChangzhouZhenjiang-Nanjing urban belt and the Hangzhou Bay city agglomeration, is the core supporting space whether in terms of the intra-region green technology flow or inter-region green technology flow. Beijing-Tianjin area and the Pearl River Delta are not only the main external purchasers, but also the main external suppliers of green technologies in the Yangtze River Delta. The ecological green integration of the Yangtze River Delta under the inter-city green technology flow has been realized at the overall level and the green technology sales level, but it has rapidly declined in the green technology supply chain.