Abstract: Construction of spatial maps for water systems is essential to maintain ecological balance in the water cycle, to optimize water resource allocation, and to enhance flood control．In this study spatial information, remote sensing, and computer technologies were utilized, along with high-precision DEM and remote sensing data, to develop methods for dynamic water system extraction, spatial verification, catchment division, coding, and map generation． A national database for spatial maps of water systems with drainage areas larger than 10 km² was established． Catchment divisions are refined to the fourth, fifth, and sixth levels, spatial relationships are modelled, to support multi-scale hydrological analysis． Automated generation of schematic maps and multi-level visualization were achieved by standardized symbology． A seven-indicator evaluation matrix was used to assess water system characteristics． This improved data accuracy, enriched small watershed information, and provided strong support for water resource planning and management, to contribute to the development of water management informatization．