Abstract: TIG cladding was carried out on the surface of 35CrMnSiA steel using HS201 welding wire.The content of Fe in the cladding layer and the microstructure of the interface between copper layer and base metal were analyzed.The evolvement and development of the distribution and the shape of the Fe in the cladding layer was investigated sy stemically.The results show that with the increased welding current, the content of Fe is increased and the shape is transformed qreatly.The shape of Fe is granular and treeing-like in the cladding layerwith the welding current below 270A;the shape of Fe is changed strongly and the large spherical Fe particle appears in the cladding layerwith the welding current surpassing 300 A.Under the effect of the arc force, the liquid Cu and Fe is mechanically mixed and the configuration of the solidified microstructure is the inclusion of Cu and Fe.