The Xiangfan—Guangji fault（XGF） which separates the Dabie orogen belt（DOB） from the Yangtze block is the south boundary fault of the DOB. The XGF is divided into two parts by the Jianghan rift basin. The western and eastern parts of the XGF show significantly different structural features. The western XGF is characterized by typical Ndipping listric margin fault that has a thrust displacement of at least 30km, while the eastern part underwent more complex tectonic evolution. After a similar initial southward thrusting with the western part, the eastern DOB made a largescale southwestward thrust onto the North Yangtze foreland basin along the XGF in late Jurassic. The low angular Ndipping XGF was then rebuilt by succedent northward compression from the Jiangnan uplift while the deep still shown southward thrusting features.New field structural data, 40Ar/39Ar ages, zircon LA-ICP-MS ages and sedimentology evidence indicate that the XGF have experienced twice significant southward thrusting since Middle Triassic: 40Ar/39Ar ages indicate that both the XGF and the Huwan detachment, south and north margins of the DOB respectively, were formed contemporaneously as a result of the initial extrusion of UHP from mantle to lower crustal level during the continental—continental collision stage in Early Triassic（about 240~231Ma）; the second apparent thrusting was in Middle—Late Jurassic（about 160~140Ma） before the DOB’s thermal doming extension for the granitic intrusion during this period wasn’t involved into deformation. The first thrusting was characterized by inner orogen ductile, Brittle—ductile deformation accompany with exhumation of UHP terrains while the second was characterized by largescale（thrusting distance＞60km） lowangle shallow thrusting of the south margin of the DOB against above the North Yangtze foreland. During this period, extension of the north margin, largescale thrusting of the south margin together with the contemporary sinistral strikeslip of the east margin of the DOB draw a clear tectonic framework and indicate a clockwise rotation of the eastern DOB.