Abstract: The geodatabase is the third generation geographic spatial data model. Its functions have been enlarged greatly compared with Coverage,the second generation data model. After the reviews of the content of municipal,the drainage system planning and the applications of GIS to this areas,the advantages of integrating geodatabase with municipal drainage system planning are analyzed,and one new solution to municipal drainage system planning is proposed. In the layout planning of the project,the Beijing sewage treatment plants,the method is applied successfully,and proved more efficient than the traditional planning platform-CAD,the second generation data model in municipal drainage system modeling,planning data management, planning efficiency,etc.