Abstract: This paper defines the concept of the semantic grid and advances the semantic grid architecture of spatial information systems (SGASIS). The grid architecture has three layers, the fabric layer, the grid management layer and the application layer. The most important parts of the grid architecture are ontologies and the ontology transforms bridge. The transform bridge transforms ontology concept between local ontology and general ontology so as to encapsulate the local GIS and domain application and ensure that all operations are based on semantic. One example provide a detailed way on how to design a resource management system on the semantic grid. In conclusion, the semantic grid of spatial information system can improve the ability of the integration and interoperability of spatial information grid.