This paper discusses the demands for tasks and data of soil and water conservation monitoring in developmentand construction projects,puts forward an indicator system for soil and water loss monitoring,and designs an information system based on 3S techniques ( remote sensing,geographic information system,and global positioning system) . The system gathers functions of datum collection,processing,management,and application. It can printordered formattables,statistical tables and figures,and thematic maps. Being tested and used,the system is proved to have good performance and applicability.