Abstract: 3-dimenional geological model provides the base for the 3-dimenional ground water modeling in the Cretaceous Artesian basin(CAB)of the Ordos Basin.State-of-the-art code,GOCAD was used,due to large scale and complexity of the study area.The geological model was developed based on the existing borehole data,geophysical data and geological maps stored in ArcGIS database.The surface model was constr ucted on the digital elevation model and other models for the water-bearing formations and geological bodies of the Cretaceous were developed using discrete Smooth Interpo lation technique.Judging from the error analysis,t he model reaches the requirement of the current study and varies the feasibility of the model development methodology.