The Fei’eshan tungsten and molybdenum polymetallic deposit located in the eastern region of Guangdong province is a prospecting potential deposit newly discovered. Intense tectonic and magmatic activities are frequent during Yanshanian in this area. The ore bodies occur mainly in granite and greisens, which controlled by faults of NE and SN and the types of deposit contain quartz vein type and greisens type. Re Os isotopic dating of six molybdenite samples collected from the main ore body in Fei’eshan deposit show that a) the model age is from 1365Ma to 1423Ma, b) the isochron age is 1426±63Ma, and c) weighted average of model age is 1394±22Ma. It can thus be considered that the deposit formed in the third stage of Early Yanshanian and ore forming age is consistent with the monzonitic granite in orefield. According to the rhenium content and the ratio of rhenium and osmium of molybdenum samples, origin of the ore forming materials of the deposit derived from the crust. Besides, through combined with some isotopic ages of other deposits in adjacent area, it can be inferred that the metallogenic materials of the Fei’eshan deposit originated from the highly evolved melting type Yanshanian granite mass.