Abstract: This paper examines the problem of active faults in relation to geological engineering studies. In addition to the problem of faults,a discussion,classification,and evaluation of the various types of active faults and a discussion of concrete methods of evaluating active fault systems is also given. Each of these is of great significance to geological engineering in the selection of choice sites for important major construction projects such as location of a nuclear station,location of a high-energy accelerator,location of a key large-scale hydro-electric power station,and the location of thermal power plants,also included in this study are engineering studies for planning,construction and arrangement of new cities.