To cope with the storage and management of mass data in the digital basin model system, the authors proposed an approach of database construction based on ArcSDE spatial data engine. The spatial data dynamically integrated with the attribute data are managed by the relational database. Having been loaded in line with corresponding rules, the spatial data and attribute data were associated by relationship classes. And the object-oriented method was employed to manage various classes of data in order to ensure the object consistency and the database maintenance and expansion.