Gao'aobei tungsten—molybdenum deposit, which are related genetically to granites , have been formed in the southern Hunan Province. However, the ages of W-Mo mineralization and granite crystallization are poorly understand at present. This study provides the first highly precise dating of the mineralization and rockforming in the Gao'aobei W—Mo ore. The dating of zircon from Gao'aobei biotite granite determined by SHRIMP yield ages of 222.1 2.0 Ma. Hafnium isotope data was also acquired through laserablation multicollector ICPMS analysis of zircon, with the aim of gaining insight into the age and nature of the source region of the pluton. The yield age (222.1 2.0 Ma) confirm that this biotite granite intrusion belongs to late Trassic. Hafnium analysis shows the biotite granite to have negative and variable εHf(t) values (-4.7 to -10.9) and Palaeo—Mesoproterozoic (1.6 to 2.0 Ga) depletedmantle model ages, which is interpreted to reflect derivation from old crust source. The source region for these magmas may be tentatively correlated with Palaeo—Mesoproterozoic material of the South China Block, Which has been suggested to underlie the Hunan; however, further work is necessary to demonstrate this suggestion. Rhenium and osmium isotopic dating of molybdenite from the Gaoaobei tungsten—molybdenum ore by ICPMS yields isochron ages of 157.3 6.6 Ma on the 187Re versus 187Os correlation diagram. The result s suggest that the timing of W—Mo mineralization and granite crystallization are different period, W—Mo mineralization period is corresponding to the time of the large scale mineralization regionally in the Mesozoic. In addition, there exists an apparent time difference between W—Mo mineralization and granite crystallization.