Abstract: As a vital component of the earth′s biosphere, inland water ecosystems provide essential ecosystem services for the survival and development of human society.The native species within these ecosystems form the fundamental basis for these ecological services.Against the backdrop of global environmental change and intensified human activities, inland water ecosystems are facing unprecedented pressures and challenges across multiple spatial scales, including global, watershed, and regional scales.Therefore, a scientific and accurate understanding of the integrity of inland water ecosystems holds significant theoretical value and practical importance for formulating effective strategies and measures for ecological governance and conservation.This paper systematically reviews the evolution and development of the concept of integrity, proposes a scientific definition of inland water ecosystem integrity, and constructs a conceptual framework for its practical application.The framework includes core components such as scale definition, conceptual model development, key indicator selection, quantitative assessment, and adaptive management, offering a perspective for the systematic practice of water ecosystem integrity.Ecosystem integrity is not only a critical concept for understanding aquatic ecosystems but also an effective tool for implementing systematic watershed governance.Given the complexity, uncertainty, and dynamic nature of inland water ecosystems, future research should strengthen interdisciplinary collaboration, continuously improve theoretical systems, innovate technical methods, and promote the deeper application of ecosystem integrity in watershed governance.