Abstract: The Getengao Tungsten-Molybdenum polymetallic deposit in southern Jiangxi Province is a typical hydrothermal quartz vein type deposit. The ore bodies of Getengao deposit are mainly occured in the Yanshanian granite and controlled by NW and EW striking faults. In this paper, the Re-Os isotopic dating of six molybdenite samples which collected from the main ore body in Getengao deposit was carried out. the results yield a ¹⁸⁷Re-¹⁸⁷Os isochron age of(159.0±0.4)Ma, with a weighted average age of(162±2)Ma(MSWD=1.3), representing the mineralization age is early Yanshan Period, which is concurrent with the regional metallogenic events. The high Re/Os ratio(>4)and low ¹⁸⁷Re content((69.0～625.4)×10^-9)indicate that the metallogenic material was derived from the crust. We suggest that the formation of the deposit is genetically related to the interaction between differentiation and evolution of the crustal-derived granites of the second stage Yanshanian and the hydrothermal process of the granites during lithosphere extension in South China.