The Tanshang molybdenium-polymetallic deposit in Daixian County of Shanxi Province is one of the most typical ore deposits in Wutai Mountains-Hengshan Mountains polymetallic ore-forming area within the northern part of North China Craton. On the basis of an investigation of the geological features of the deposit, Re-Os isotopic dating was conducted for seven representative molybdenite samples. Thus the isochron age is interpreted as the formation time of the molybdenite, i.e., Mo-polymetallic mineralization occurred in Early Cretaceous.Similar to other Mo deposits in the Wutai Mountains, Hengshan Mountains of the northern part of North China Craton, the Tanshang molybdenium-polymetallic deposit was closely associated with the Yanshanian large-scale tectonic-magmatic activity and related to the thinning of the North China Craton since Mesozoic.oft-com:office:office" />