The mineral resources are rich in Greenland. More than 800 metal deposits or points have been proven. It has important prospecting potential, and many major world's mining companies positively participate in the prospecting and development. Therefore, it has important theoretical significance that selecting typical areas to carry out in depth study for further prospecting. The traffic of Nassaq，southwest Greenland is convenient. Based on the systematic field geological survey, we collected amphibolite rock samples containing molybdenite. And then researched the Re Os geochronology，providing the fundamental basis for the study of the mineralization and related issues. The age of molybdenite formation is 2553 Ma，a product of the late Neoarchean. The mineralization occurred when Qorqut granite intruded. We should pay attention to the prospecting and evaluation of molybdenite related Qorqut granite in the southwestern Greenland.