The Nuri skarn Cu-W-Mo polymetallic deposit is located in the Kelu-Nuri-Chongmuda copper polymetallic belt on the southern margin of the Gangdese metallogenetic belt of the Tibet Plateau, which is characterized by large-scale mineralization and unique assemblages of mineralization. It can be divided into Cu-Fe ore section and Cu-W-Mo ore section. Recent studies show the timing of mineralization between Cu-Fe and Cu-W-Mo ore section is different, which means that there are two stages of mineralization in Nuri at least. In this article, we found an unique type of orebody which only contains chalcopyrite without Mo and W mineralizations. Meanwhile, this type of orebody is characterized by straight quartz vein which contain a large amount of chalcopyrite and biotite. Biotite from the Nuri Cu-W-Mo ore section yielded a well-defined 40Ar/39Ar plateau age of 23.75±0.18 Ma and an isochron age of 23.72±0.28 Ma ( MSWD = 1.5 ), which represents the formation age of chalcopyrite, and consistent with the formation age of molybdenite intergrowth with chalcopyrite. Based on this, there is only one mineralization event in Cu-W-Mo ore section in the Nuri deposit. The mineralized quartz vein shows extentional setting, which may represent migration channel of metallogenic material. Therefore, we suggest that the Kelu-Nuri-Chongmuda metallogenetic belt took place large-scale mineralization in late-collision stage, and formed a uniform porphyry-skarn ore-forming system with great exploration prospect.