Abstract: Through a specific example as shan-shui-wen-yuan residential district in Xin-tai city, the study introduces the geological survey of the suspected active fault found in the foundation excavation of a new civil building. Combined with engineering exploration, trench excavation, high-density electrical prospecting, and analysis of the strata dislocations that covered the fault, we identified the activity of Xintai-Mengyin fault, and gave the following results:The Xintai-Mengyin fault is a mid late Pleistocene active fault and a left lateral strike slip positive fault. We evaluated the affections on buildings, and put forwarded reasonable opinions and suggestions for the planning layout and foundation design of the district. This study is a specific application of fracture activity identification in planning, design and engineering construction, and achieved good results, it is of reference to other related projects.