Abstract: Owing to special needs in numerical modeling of groundwater flow, a new approach for automatic generation of triangle mesh is presented, in which some specific inner restrictions are considered during the course of automatic mesh generation. Two types of inner restrictions including fixed nodes and fixed element boundary are given so as to generate a series of nodes and relation array between existing nodes. The procedure of triangle mesh generation is stated in detail. This method can automatically, quickly provides various necessary discrete data in the simulated zone in numerical modeling. Besides, the calibration of triangular mesh and the extended approach to quadrilateral mesh are also discussed.