Abstract: Henan Ruyang molybdenum lead-zinc polymetallic ore field with development of Donggou giant porphyry Mo deposit, Zhuyuangou large Mo deposit and some large lead and zinc deposits including Laodaizhanggou, Xizaogou and Wangpingxigou, is located in east Qinling molybdenum metallogenic belt which is located in southern margin of North China. It is one of famous metallogenic deposits concentration area in China. In this paper, the geological characteristics of Zhuyuangou large Mo deposit are introduced in detailed. Re-Os isotopic dating of molybdenum shows that the Re-Os model ages of the deposit are between 122.2±2.3Ma~119.6 ±2.2Ma, an average of 120.9±2.3Ma. This age is in good agreement with the ages(120~112Ma) of molybdenum lead-zinc polymetallic deposits and intrusions in southern Ruyang. Based on these geochronological data, we propose that these deposits and intrusions in southern Ruyang occurred at the same geodynamic framework that is intraplate extensional environment during the large-scale extension period of lithosphere of eastern China in Late Mesozoic.