Abstract: “Luanxian-Leting fault”is an inferred fault. Recent petroleum geophysical data reveals that the “Luanxian-Leting fault”does not exist in the east of Changli fault. Based on the field geological investigation and comparative analysis of the northern segment of the“Luanxian-Leting fault”(in this paper, the West Luanxian fault) and the Leting fault, it is found that the West Luanxian fault and the Leting fault are two independent faults. There are obvious differences between them in the occurrence, property, development history, structural location and the latest activity. The southern end of the West Luanxian fault is likely to end on the Lulong fault, and the deep part is in the shape of “y” . Both of them constitute the seismogenic structure of the Lulong earthquake. The shallow seismic exploration of Leting fault shows that the depth of the upper breakpoint is between 279—612 m, which may have been active in the early Quaternary, but not since the late Pleistocene.