Using the GIS platform of Mapinfo, the authors developed the coupling system of GIS and groundwater numerical simulation (GISFEM) and achieved the coupling of GIS and groundwater numerical simulation successfully, on the basis of a thorough study of the examples of successful applications of GIS in hydrology and hydrogeology. The system has made up the defaults of GIS in the specialized analysis of hydrogeology, and it can expediently calculate the degree of contamination and construct rose diagrams of groundwater samples，analyze the statistic data， and draw statistic graphs. At the same time，the automatic gridding function of GISFEM and the pictorial display of calculation results greatly reduce the artificial w orkload of classic numerical simulation of groundwater and enhance the ability o f model recognition.This paper introduces the design，structure and main functions, development methods and course of the coupling system in detail