Abstract: Point set used for fault modeling from different sources vary in its characteristics,which influence on the approach and methods in modeling.Aimed at applying 3D fault model to 3D GIS,the information structure in modeling point sets such as geological observations,drilling holes,sections and ichnographies were analyzed.The modeling methods and flows for 3D fault models on point sets from different sources were presented.Since the original point sets such as geological observation and drill holes express the spatial characteristics of faults indirectly,the reconstruction for point sets were performed by means of constructing the mathematical models such as plane,curved surface and curved line for fault surfaces,strata surfaces and the intersecting lines between fault surfaces and strata surfaces.The point sets for independence fault modeling were reconstructed by means of dispersing the continuous models.Point sets from sections and ichnographies can be used in modeling directly.Taking the duo-TIN faces model as an example,the modeling methods for 3D fault were illustrated