Abstract：Three-dimensional strata information system(3DSIS) is a system for storing，managing，checking，manipulating and displaying data which are spatially referenced to the underground strata. But the grids for visualization in 3DSIS are triangular prisms and can’t be directly used in finite element method. Based on the principle of mesh generation in FEM，the reasons are given that the visualization grids in 3DSIS can’t be used in FEM. A local-whole(L-W) model which is suited to 3D visualization and FEM is put forward. Using the L-W model，the grids are easily changed into the meshes of FEM. The key points that control the stratum shape are obtained by the topological analysis，and then lines and areas are defined，and solid model features are generated from the bottom up，and then new grids are regenerated. An integration system of 3DSIS and FEM is developed by the method of mixed-language programming using FORTRAN and Visual C++. And at last，the application of the integration model is given.
