Abstract: Based on the summarization and analysis to present methodologies of 3D modeling of the geological faults, a new method named rock pillar body partition (RPBP) modeling is put forward on GTP (generalized tri-prism) basis for 3D spatial modeling of faults. The RPBP method takes borehole data as its original data source, and the modeling process includes the steps as follows. Generate the constrained Delaunay TIN (CD-TIN) of terrain in accordance with the collar data of borehole and the outcrops of faults. Construct the limiting triangles in each rock pillar body (PRB) according to the types and modeling priority sequences of the fault system. Develop the 3D faults spatial model in accordance with the limiting triangles. The programming test showed that the RPBP method can accurately describe the complicated fault system involving obverse and reverse faults and its inter-clipping, and is smartly as well as reliably to construct interactively the 3D spatial modeling of complex fault system.