Abstract: The synthetic space database of hydrology,engineering and environmental geology in 1:50000 scale for key cities and economic developing zones is an important component part of the Digital Land Program.During the establishment of such a database for Dalian region,we take the MAPGIS system as the operating platform,by inputting the basic vector data,editing the graphic elements(dots,lines,ets.),correcting errors,constructing graphic layers and connecting the attribute to graphs,then converting projection and format,finally accomplish the synthetic space database.It provides an important basis for further spatial analysis and multi purpose development and application.