Abstract:TheBeishan orogen, located in the southern Central Asia Orogenic Belt (CAOB), mainly consists of a series of subductionaccretionary complexes. Some Precambrian rocks are sporadically distributed within the wide accretionary zone of Beishan. Due to the metamorphism and deformation during the strong orogensis and subsequent intracontinental orogensis since the Paleozoic, it is difficult to distinguish the Precambrian rocks and the products of orogensis in Beishan. Thus, the Precambrian affinity in the Beishan orogen is still controversial. Based on detailed field work, we carried out petrographic, zircon U-Pb geochronological and Hf isotopic analysis on Precambrian metasedimentary rocks from the Mazongshan block in the central Beishan area. The relatively high metamorphic degree, rock assemblage and detrital zircon UPb age spectrum show significant differences from that of Paleozoic passive continental margin products, indicating that the metasedimentary rock in Beishan is remnant part of the Precambrian basement rocks formed between ~1.1 and 1.66 Ga. Combined with previous studies, the following understanding can be summarized: the Beishan area presents similar features as the Tarim and Mongolia blocks in material sources, suggesting that the three involved into the assembly and break-up event of the Rodina supercontinent after the Neoproterozoic, but show multiple sources before the Neoproterozoic (>1.1 Ga). The Mesoproterozoic parametamorphic rock in the Beishan orogen in this study shows that it is different from the Tarim craton, but similar to the Mongolia block. The Hf isotopic analysis further reveals that the Precambrian parametamorphic rocks and Dunhuang block in the Beishan orogenic belt all record the history of newborn crust event during the middle and late Paleoproterozoic and show differences from the Tarim craton. This also implies that the Dunhuang block and the beishan orogenic belt probably have a uniform Precambrian basement before the Mesoproterozoic (~1.58 Ga).