Abstract: Exploring the complexity and dynamics of the spatial association network of urban ecological resilience can provide a new research perspective for achieving ecological collaborative development in the Yangtze River Delta Region (YRDR).This study used 41 prefecture-level cities in the YRDR as the research samples, and performed a measurement of urban ecological resilience levels from 2013 to 2022.The entropy weight-TOPSIS method was adopted.A spatial association matrix was constructed, and the social network analysis was employed to examine the evolution characteristics and driving mechanisms of the urban ecological resilience.The results showed that: (1)The overall level of urban ecological resilience in the YRDR had steadily improved, and the range of high-resilience areas had gradually expanded.However, regional disparities remained evident, showing a spatiotemporal distribution pattern of high resilience in the southeast and low resilience in the northwest.The spatial association network had gradually formed, and the overall network connection density had increased, showing the features of intensification and multicentralization.(2)The overall network structure had become tighter and more stable.The core cities (such as Shanghai and Hangzhou) played a key role as central actors and intermediaries in the network, and displayed a "core-periphery" spatial distribution.The urban ecological resilience spatial association could be divided into the net spillover, main beneficiary, and "broker" sectors.The distribution of members in these sectors aligned with the geographical characteristics of the Yangtze River Delta's core economic zone, central connecting belt, and peripheral hinterlands.(3)Socio-economic factors such as economic development, technological innovation levels, foreign openness, and policy regulation had a significant impact on the formation of the urban ecological resilience spatial association network.