Fault gouge has potential implications in the study of fault actions because such tectonic materials are normally produced with fault activity. The distribution of para-Fe²⁺ and para-Fe³⁺ in the fault gouge produced by the fault activity of different times reflects different Oxidation and reduction environment,which provides the possibility to study the activity of the fault. Various gouge samples were collected from a naturally outcropped profile of the Huangxian Arc-type Fault at the Changzhuzi Beicun of Huangxian Country,Shandong Province,and analyzed for iron species using a Bench-MB500 Wissel M ssbauer Spectroscopy. Based on the general tectonic properties and activity identification of the fault,and fault materials for active times,the characteristics of iron speciation of the fault materials and their significance to seismic geology were discussed in this paper. All evidence revealed that the central part of the relatively younger fault gouge was rich in high-spin paramagnetic ferrous iron(para-Fe²⁺)whereas the relatively older gouge on two sides were mainly composed of low-spin paramagnetic ferric iron(para-Fe³⁺). All geochemical properties of iron in the fault gouge samples showed close relationship to the evolution and activity history of the fault,indicating some complexed water-rock interactions occurred within the fault zone. Those results will supply a new method for the analysis of newly-old orders of faults and their active processes by using the elemental geochemical properties of iron in fault materials,and also showing valuable distribution and implications.