Abstract: A Neogene left-lateral oblique turst fault-Sertengshan-Xitieshan oblique trust zone is recognized in the northern margin of Qaidam basin based on the analysis of structures of the area.This oblique trust fault zone with northwestern -southeastern trending consists of fault gouge,fault breccia and fault cleavage.Fault hanging wall is Sertengshan -Xitieshn napple,which is distribution in dextral en echelon.Fault footwall consists of Youcangshan Formation in Neogene.It is discussed that geological setting of the oblique thrust faults zone,is considered in connection with the long distance effection of Himalayan orogenic belt intracontinent subducting.