Abstract: In the eastern Oilian orogenic belt of Baiyin area,Gansu,we discovered two NNE directive ductile shear zones that ranges parallelly through 1:50000 geological mapping. According to the characteristic of geometric conformation and microscopic fabric,it is suggested that zones are right-lateral strike-slip shear and opposite "S" suture progeny formed by oblique collisions of Qilian and Qinling orogenic belt at terminal Caledonian. At the effect of structure and magmatite in this district,it finally formed by st rike-slip of different continental blocks.