In response to the controversy over the early Permian tectonic setting in the southeastern Central Asian Orogenic Belt (CAOB),this study conducts systematic petrological,geochronological,geochemical,and zircon Hf isotopic studies on the metamorphic plutonic assemblage within the originally defined “Shuangjing paleocontinent” along the Xar Moron River. The plutonic assemblage is mainly composed of gabbro,diorite,granodiorite,and granite,with zircon U-Pb ages mostly ranging between 296 and 270 Ma. Based on regional geochronological data,it is determined that there are no Precambrian geological bodies within the “Shuangjing paleocontinent”,thereby ruling out its tectonic attribute as a Precambrian ancient block. Although the rock assemblage shows a bimodal feature in the TAS diagram,the Early Permian plutons generally have relatively low total alkali (Na₂O + K₂O) and K₂O contents,belonging to calc-alkaline,high-K calc-alkaline and low-K tholeiitic series respectively,rather than the typical alkaline series in rift settings. In addition,the trace element distribution patterns of mafic magmatic rocks generally show depletion of the high field strength elements (HFSEs),such as Nb,Ta,and Ti,indicating the characteristics of subduction zone magmatic rocks. In the normative mineral classification diagram,the granitoids mainly fall within the tonalite-trondhjemite-granodiorite (TTG) field,which is commonly associated with active continental margins. Zircon Hf isotopic analyses further reveal that different gabbros originated from the asthenosphere and continental lithospheric mantle,respectively. And different granites were primarily derived from either juvenile crust or ancient crustal materials. Considering the close spatio-temporal relationship between the magmatic assemblage and the Xar Moron River ophiolite belt to the north,it is proposed that the observed bimodal magmatism and the variations in zircon Hf isotopic composition of different plutons resulted from the upwelling of the asthenosphere triggered by the delamination of the subducted Paleo-Asian Ocean slab. The asthenospheric upwelling further induced extension along the northern margin of the North China paleoplate and caused partial melting of different lithospheric layers.