Various kinds of complicated tectono-geochemical processes always occurred in active fault zones along with their formation and evolution, which showed many abnormal phenomena such as the growth of stress minerals, the formation of surface micro-appearances of mineral particles in the fault gouge and/or rocks, gasous isotopic anomaly and so on. Systematic researches on the abnormal phenomena could be helpful to obtain significant information on the activity, opening and sealing properties and the three-dimensional layout, especially the fault depth etc. in active fault zones. Because active fault zones are normally very complicated with numerous physical-chemical processes, there are still large space and challenges for geochemical researches on fault gouge, fluid geochemistry, and water-rock interactions in the active fault zones.