Abstract: The Dayinjian molybdenum deposit, located in north margin of the Dabie Mountain, is a porphyry-skarn-vein type deposit. In this paper, four molybdenite samples selected from this deposit have been used for Re-Os dating by the inductively coupled plasma mass spectrometry (ICP-MS), and the dating yielded of a Re-Os isochron age of 122.4±7.2 Ma, indicating the molybdenum mineralization occurred in Early Cretaceous. Moreover, the Re isotopic contents of molybdenite samples indicate that the ore-forming materials are likely to be mainly derived from the lower crust. The Dayinjian molybdenum deposit is developed in the regional extensional regime while the lithosphere thinning occurred in Mesozoic in the central-eastern China, which is a component part of the large-scale metal mineralization in the eastern China.