Abstract: Arc constriction is an effective approach to enhance the heat intensity of TIG(tungsten inert-gas)arc.A novel approach to constrict the TIG arc was presented.By means of double ceramic plates with parallel rotation, the arc near the electrode was constricted.Through observation of the arc shapes and measurement of the welds cross-sections, the arc shapes and its heat characteristics have been investigated at a variety of constriction conditions given by the rotating ceramic plates.The results show that the axially asymmetrical constriction of TIG arc was made by rotating ceramic plates.In the direction perpendicular to the rotating plane of ceramic plates, the central current carried column of the arc was constricted stably.Decrease of the distance between two ceramic plates, and increase of the depth for the arc entering into the ceramic plate gap gave rise to the further constriction of the central current carried column of the arc, and in turn increase the penetration of welds.Furthermore, the arc voltage was increase slightly when the constriction extent became stronger.