Abstract：The southern section of the Tangxi fault of the Taihang Mountains is studied by means of troughing, dating test, terrace survey and deformation measurement monitoring. The activity characteristics of the southern section of the Tangxi fault are analyzed and discussed. The results show that the Tangxi fault developed in the Middle Pleistocene and experienced many activities. The activity intensity in the southern segment of the Tangxi fault is relatively high,and the fault does not extend to the Late Pleistocene strata. The era of latest activity of the southern section of the Tangxi fault is the Middle Pleistocene. The results of vertical deformation monitoring of Xidaicun site in Tangxi fault (1999-2014) are abnormal. Based on the data of all monitoring points and regional neotectonic characteristics, the abnormality may reflect regional deformation in the working area, not caused by Tangxi fault.