Abstract: The northern boundary of the Qinling orogen is demonstrated by many pieces of evidence to be a huge intracontinental subduction zone where the southern North China Block underthrust beneath the Qinling from north to south and extended down below the Moho. This intracontinenta1 subduction zone is wel1 revealed by seismic reflection profiles across the eastern Qinling in western Henan provinee. North-directed thrust systems were developed in the middle and upper crust in association with the subduction zone, extending over 1000 km along their tectonic strike from Baoji eastward to Tanlu fault and probably connecting with the thrust system on the northern edge of the Qinling orogen to the west. The intracontinental subduction zone formed during the Cretaceous and then controlled the Mesozoic-Cenozoic tectonic evolution of the region between North China B1ock and the Qinling. Present three-dimensional lithospheric framework of the Qinling can be described as a flyover-type structure with three rheologically different layers, as revealed by geological, geochemical and geophysical studies. The upper layer, from 0-20 km, is actually a zone with brittle, viscoelastic and ductile deformation, and featured by antecedent E-W -striking lineament. The middle layer from 20-80 km is a zone typfied by flat rheological layering, including the Moho. The lower layer below the depth of 60-80 km is in adjusting upper mantle and characterized by N-S striking geophysical anomaly zones. The N-S-striking structures in lower layer, resulted from active adjustment of upper mantle materials, pass upwards to the antecedent E-W -striking lineaments in the upper layer through a middle flat rheological zone, showing a crosscutting relationship of structures in upper and lower tectonic layers of the Qinling lithosphere, so-called flyover-type 3-D framework. As its northern boundary, this intracontinental subduction zone is a basic component of present lithospheric framework of the Qinling orogen. It formed in the same dynamic regime as other Mesozoic-Cenozoic structures. Active deep mantle dynamic processes in the Qinling region are controlled by the interacting between three adjacent major plates, i.e., north-moving Indian plate, west-subducted Pacific plate and south-moving Siberian plate. The mantle activation exerted strong influence on the upper crust, resulting in rapid vertical uplift, lateral accretion, and modification of old structures. The present flyover-type 3-D framework of the Qinling is built up by joint action of tectonic processes of different crust-lithospheric layers and represents one type of orogenic structures preserved through long-term geological evolution.