Abstract: Different molybdenites were collected from the Jiama copper polymetallic deposit for Re-Os isotopic dating. The isochron age of (15.34±0.10) Ma, and model age of (15.21±0.22) Ma～(15.50±0.22) Ma were obtained. This results are similar to the data from the previous Re-Os dating results, which indicates that the mineralization age of molybdenites in Jiama is around 15 Ma. According to Re-Os dating results of other molybdenite from porphyry copper deposits in Gangdese belt, which is considered to have the similar mineralization age with that of the Jiama copper polymetallic deposit, it provides a reference for further study on geological genesis of the Jiama copper polymetallic deposit and a theoretical basis for deep earth prospecting of porphyry-skarn ore bodies.