The studied copper(molybdenum) deposits include the Anjishan copper deposit and the Tongshan copper-molybdenum deposit, of which the former lies in the inflexion section of Nanjing-Zhenjiang Mountain arcuate structure, and the latter lies in the middle part of the same mountain chain. Both are medium-size ones. Associated with granodiorite porphyry and quartz diorite porphyrite, the Anjishan copper deposit is mainly of porphyry and skarn type. The single mineral (biotite and hornblende) K-Ar isotope ages of Anjishan rock bodies are between 123.1×106a and 106.0×106a,and K-Ar isochron dating gives an age of 123.0×106a. The Tongshan copper-molybdenum deposit is mainly of skarn type associated with quartz diorite porphyrite, whose K-Ar isotope age is 117.0×106a. Two pure molybdenite samples were collected from fine-grained disseminated ores of Anjishan and Tongshan deposits, with the former determined as 2H1+3Rpolytype and the latter as 2H1by means of XRD analysis. 187Re and187Os contents of molybdenite from the two deposits are determined by Inductively Couple Plasma Mass Spectrometry (ICP-MS), with Re-Os ages calculated by using the formulaλ (187Re)=1.64×10-11a-1. The results are 108×106a for the Anjishan deposit and 106×106a for the Tongshan deposit, which are both younger than the ages of the associated magmatic rock bodies, with the differences being 15×106a (Anjishan) and 11×106a (Tongshan) respectively.