Abstract: The integration of geographic computing model and geographic information system (GIS) is the technical difficulties of experimental geography. Geographical systems, having rich content, complex structural and diverse functions, gave rise to the challenge of geographic system analysis and simulation. In this paper, to solve these problems, such as geocomputation model focused expression, geographical analysis model focused on modeling, and blindly selected geographical simulation model, the author put forward the concept of a geographic system simulation basic model (GSBM) after analysing the demand of geographic calculation, cartography  and geographic information science.GSBM is composed of GISbased platform, pointmultiagent (AB), surfacecellular automata (CA) and flowsystem dynamics (SD).The framework, structure and communications of GSBM are discussed and the principle of the model, the integration of key technologies and application ways are analyzed deeply. This article provides a reference framework for the research and development of geographical system simulation platform in future.

Key words: geographic system simulation, agentbased, cellular automaton, system dynamics, geographic information system