Abstract: Small and micro water bodies are widely distributed in urban and rural settlements, agricultural landscapes, urban landscape spaces,riparian zones of rivers and lakes,and lake-wetland transition areas. Despite their limited individual spatial extent,they play significant roles in regional water catchment,conveyance,drainage and storage,as well as in non-point source pollution interception,habitat maintenance,and landscape connectivity. Compared with medium-and large-scale water bodies such as rivers,lakes,and reservoirs,small and micro water bodies are characterized by large quantities,scattered spatial distribution,fragmented boundaries, diverse types, and pronounced susceptibility to anthropogenic disturbance and complex surface backgrounds. Consequently,their monitoring has long been constrained by difficulties such as being “observable but difficult to quantify”,ambiguous boundary delineation,and challenging identification. As the focus of ecological and environmental protection and governance gradually extends from major rivers and key lakes and reservoirs to headwater areas,terminal drainage units,and micro-scale spatial units,small and micro water bodies have become important targets in ecological and environmental monitoring,river and lake chief system management,rural habitat improvement,and aquatic ecological restoration. Although existing laws,regulations,standards and normative documents provide a basis for the identification of small-scale wetlands and water-related objects,a unified, explicit, and operational definition of small and micro water bodies that directly supports remote sensing identification and environmental governance remains lacking. In this context,this paper,drawing upon relevant laws,regulations,standards and normative documents,and regional water-body characteristics,proposes a conceptual definition of small and micro water bodies oriented toward ecological and environmental monitoring. It systematically reviews the main characteristics and methodological advances in remote sensing extraction of small and micro water bodies. Taking Anxin County in the Baiyangdian region as a case study area, this study develops a technical framework encompassing multi-feature integration, multi-method extraction,rule-based post-processing, and accuracy assessment. The results are expected to provide theoretical support and methodological reference for the identification,survey,and governance of small and micro water bodies oriented towards ecological and environmental monitoring.