In this paper, detailed field work and systematic study of typical ore deposit dissection was carried out on molybdenum deposit in eastern Qinling. The ages of intrusive rock in the Nangou molybdenum deposit were determined by zircon UPb analysis with LAICPMS, while ages of Baishijian and Mabohao molybdenum deposit were determined directly by ReOs method with molybdenite using ICPMS. Based on the geochronological research, together with geological and geochemical investigation on both granite and molybdenum deposit, the origin of rockforming and oreforming materials, geodynamic background and oreforming model are discussed. Detailed microscope observation indicates that the main rockforming minerals in the Nangou molybdenum deposit are orthoclase, microcline, plagioclase, quartz with minor biotite, muscovite and sericite, and with tourmaline as the primary accessory mineral. The contents of alkaline feldspars are 50% c.a., with 40% quartz, 10% plagioclase and less than 1% biotite and muscovite.Nangou intrusive rocks are high potassic calcalkaline series, with high SiO2（71.79%～78.09%）, low TiO2（11.69%～14.89%）, rich in alkali （with Na2O content between 2.21%～ 4.26%, K2O between 4.01%～7.57%, K2O/Na2O between 1.07～3.42）, low Mg#（16.44～42.50）and CaO（0.2%～1.54%）. The Nangou intrusive rocks exhibit a low amount of total rare earth elements (ΣREE), with obvious differentiation between light rare earth elements (LREE) and heavy rare earth elements (HREE), slightly negative Eu anomaly and strongly negative Ce anomaly. The strongly negative Ce anomaly may result from subduction of sediments with negative Ce anomaly, reflecting a reduced marine environment for the source rocks. The chondritenormalized REE distribution patterns are similar to those of the upper crust, indicating the involvement of huge amount of upper crust materials during the formation of the granites. The trace elements analysis of Nangou intrusive rocks shows high content of large ion lithophile elements (LILEs) and low content of high field strength elements (HFSEs), with variable contents of transition metal, obviously rich in Cu, Sc, Co. On the other hand, the intruded rocks are depleted in Ba, Sr, identical to the crust type granite, suggesting crustal origin of Nangou granite. Based on major and trace element discriminations, intrusive rocks associated with molybneum deposits have been classified into types of syncollision granites or postcollision granites. High precision zircon LAICPMS analysis shows that zircon weighted mean 206Pb/238U age in Baishijian ore body is 451.7 5.7Ma（MSWD=1.6）, while zircon weighted mean 206Pb/238U age in Mabohao group is 109.8±4.1Ma（MSWD=1.17）, implying at least two magmatic events, the first at late Ordovician（approximately at 451Ma）, the latter at early Cretaceous（approximately at 109Ma）. The ReOs geochronological dating with molybdenite shows that its isochron age of Baishijian molybdenite deposit is 103±17Ma（MSWD=0.84）, while that of Mabohao molybdenite ore body is 107.08±0.61 Ma（MSWD=0.96）, indicating the same formation period of the two ore deposits, corresponding to the largescale EW lithospheric thinning after the HuabeiYangtze collision. In the middle and late Cretaceous, largescale lithospheric thinning prevailed in east China, including eastern Qinling. Due to lithospheric thinning, juvenile hot mantle materials were injected into preexistent lithosphere by upwelling asthenosphere, increasing heat fluxes in lithosphere and resulting in underplating of basic magma in continental crust. During the underplating, ore forming fluids and materials were transported to the superface, accompanying the injection of mantle and lower crust material. When the upwelling mantle criticalsupercritical orebearing fluids invade into the tectonic weak belts, boiling of the fluids and exchange between oreforming fluids and superfacial fluids were initiated due to the change of temperature and pressure, leading to precipitation of large amounts of metals and magma. As a result, the tremendous MoCuWAu deposits in eastern Qinling were formed. The oreforming model was established and the principles of exploring MoCuWAu deposits was proposed based on in petrology and metallogenic dynamics in the Nangou molybdenum district, eastern Qinlin orogenic belt.