Abstract: North of the Devonian System in the eastern Qinling Mountains, are successively arrangedthree metamorphic suites,the Danfeng Group,Qinling Group and Kuanping Group,which are sep-arated by two regional major faults. After deposition,the three groups underwent three phases ofstrong folding,regional metamorphism and ductile shear. By referring to the results of age deter-mination,the authors propose a new idea that they were all deposited in the Early Proterozoic. Ac-cording to the sedimentary,lithological and geochemical characteristics of the three groups,it isconsidered that the Kuanping Group is backarc continenttal slope deposits,while the Qinling andDanfeng Groups are volcanic island arc deposits,all the three belonging to the front of the NorthChina plate.