The integration and interoperation of distributed inhomogeneity GIS system is the direction of GIS development. Based on the reserach of WMS(Web Map Service)

WFS(Web Feature Service) and GML

this paper presented a new XML RPC based distributed computing model of internet GIS. The Model is composed of three tiers

the diverse geo processing of geo processing enabled client

the GIS distributed computing mid ware and the geo processing server. XML RPC is used to carry out the communication between geo processing client and geo processing server by GIS distributed computing mid ware. Login?Logout?GetCapability?GetCapability?GetMap?GetFtrInfo?GetSelFtrs?GetThemeMap?GetStatMap are defined as the basic GIS computing command in XML. GML 2 0 is used to present the geo spatial data and geo processing result. The geo processing sever may implement the XML RPC interface directly

such as Web Map Serve

or use a adapter to encapsulate the geo processing service. The geo processing client uses these basic commands and their combination to call the geo processing service. The geo processing sever execute the geo processing using its own geo spatial data

application model and computing resources. Then the geo processing client receives the geo processing results as image stream and/or feature stream encoded in GML 2 0 and thus integrate the distributed inhomogeneous geo processing server system.s