Abstract: This paper develops the architecture of GIS grid, including basal grid, spatial data grid, spatial information grid, spatial knowledge grid and spatial service grid.Spatial data grid is the foundation of spatial information system(narrow sense), spatial knowledge grid and spatial service grid.The uniform management and efficient access of massive, distributed spatial data are studied with emphasis on spatial data grid.Spatial metadata, expression of spatial information, connectivity of spatial information and consistency of spatial information are studied with emphasis on spatial information grid (narrow sense). Organization and management of spatial knowledge are studied with emphsis on spatial knowledge grid. Spatial service grid provides function service for other GIS grid.The uniform management and efficient access of GIS function service are studied with emphasis on spatial service grid.