We have pioneered research on geospatial information system for national water census and its application. Aiming to the main issues such as information obtaining, data management, quality control, and project organization, the overall thought is given. It is based on taking fundamental data as supporting and data model as precursor, and viewing intelligent tool as protective role, and combing the management theory with technical methods. The key techniques developed include the digital basin extraction, data modeling orienting to the object of water resources, data acquisition and processing within certain rules and the application of multidimensional theme.