The basic facts of the Qinling orogen are that it is composed of three distinct tectonostratigraphic units, which possess different crustal compositions and textures, and evolved in differing tectonic regimes in three stages. The lower unit presents two kinds of orogenic basements. The middle unit presents a Late Proterozoic--Middle Triassic succession, which consists of depositional sequences developed at both active and passive continental margins, subduction-related ophiolites and collisional granites. All these demonstrate a plate tectonic regime in this stage. In addition, widespread basement uplift also implies the subcrustal underplating and vertical accretion. The upper unit is made up of both intruded granites and sediments deposited in foreland, hinterland, and postorogenic rifted basins. Intensive magmatism and crustal deformation indicate strong postorogenic intracontinental orogenesis during the Mesozoic and Cenozoic eras.The fundamental composition and evolution of the Qinling were built up by different orogenensis under different mechanisms throughout its history.