Abstract:The interactive stress relationship between ecological security and urbanization level within a watershed essentially reflects the interplay between humans and the environment. Against the backdrop of accelerated urbanization and increasing pressure on the carrying capacity of natural resources and the environment, lake basins are finding it increasingly difficult to provide stable material support and ecological guarantees for regional sustainable development. Within the theoretical framework of the man–land relationship in regional systems, this study conducts a quantitative analysis of ecological security and urbanization levels across various lake basins, and explores the spatial heterogeneity of their interactive stress relationship. The research findings indicate that: 1. Under the joint influence of ecological governance and regional development, the ecological security and urbanization levels of different lake basins have improved to varying degrees, with their spatiotemporal evolution exhibiting significant spatial heterogeneity. 2. Different basins experience varying degrees of stress in the interaction between ecological environment and urbanization, exhibiting distinct patterns of coupling and coordinated evolution. Developed basins tend to demonstrate a higher level of coordination, while regions with a strong ecological foundation often experience lagging urbanization. The differing levels of stress imposed and endured in the interaction between ecological security and urbanization across basins reflect regional disparities shaped by the combined influence of natural conditions and stages of development. 3. There exists a complex interactive stress relationship between ecological security and urbanization, influenced by factors such as natural endowments and stages of development. Developed basins show weakened interactive stress between ecological security and urbanization; in ecologically sound but underdeveloped basins, ecological factors strongly constrain urbanization; in ecologically fragile and underdeveloped basins, a bidirectional stress pattern emerges. Promoting ecological governance and urbanization processes in a manner tailored to local conditions and exploring development pathways with high adaptability and synergy are key to achieving high-quality development in lake basins. The study aims to systematically depict the interactive stress relationship and evolutionary characteristics between ecological security and urbanization level, in order to provide scientific reference and practical examples for sustainable urbanization and ecological civilization construction in lake basins.