Located in the central- southern Great Xing’an Range, Inner Mongolia, China, the Lianhuashan copper deposit remains controversy in its genesis. In this study, molybdenite Re- Os dating and S- Pb isotopes of sulfides has been carried out. The results indicate that the Lianhuashan deposit was formed at 139. 1±1. 1 Ma, not the Triassic documented by the previous literature. The δ 34 S V- CDT values of sulfides from the Lianhuashan deposit vary from -1. 5‰ to 5. 0‰, and have Gaussian distribution feature, which indicate the sulfur derived from deep magmatic sources. The δ 34 S V- CDT values of the Lianhuashan sulfides are very similar to other tin- tungsten- silver polymetallic deposits in the central- southern Great Xing’an Range. The lead isotopes of the Lianhuashan sulfides have a linear distribution feature in the 207 Pb/ 204 Pb vs 206 Pb/ 204 Pb and 208 Pb/ 204 Pb vs 206 Pb/ 204 Pb charts, indicating that the lead is mixture from two endmembers, one is lower in 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb, and another endmember is higher in 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb. The lead isotopic feature is also similar to other polymetallic deposits in the central- southern Great Xing’an Range. The average Re content in molybdenite of the Lianhuashan copper deposit is 1078×10 -9 , which is significant lower than that of porphyry copper deposits formed in subduction tectonic setting about two orders of magnitude, but similar to Re content in molybdenite from the Sn- W- Ag polymetallic deposits associated with highly fractionated granites in the central- southern Great Xing’an Range. The Re content in molybdenite indicates that the formation of Lianhuashan copper deposit is related to the highly fractionated granitic magmatism, rather than subduction related magmatism. The study also indicates that there is potential to find Sn- W mineralization associated highly fractionated granites in the Lianhuashan area.