In order to obtain the age and genesis of quartz diorite-porphyrites of the Deneng copper polymetallic deposit, U-Th-Pb measurement was carried out on zircons from quartz dioriteporphyrites using LA-ICP-MS technique, geochemistry and Sr-Nd-Pb isotopes. Zircon U-Pb dating yielded the ages of 126.6±2.2Ma to 127.5±2.2Ma, which corresponds to the crystallization age of quartz dioriteporphyrites. The quartz dioriteporphyrites belong to the highK calcalkaline series and are characterized by middle SiO2 and high ALK contents. The chondritenormalized REE pattern is right oblique, with (La/Yb)N of 4.64~6.18 and obvious negative Eu anomaly (Eu=0.66~0.74). They are also enriched in large ion lithophile elements (LILEs eg, Rb, Th, K, Pb, Zr and Hf) and depleted in high field strength elements (HFSEs eg, Nb, Ta, P and Ti). The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of quartz dioriteporphyrites vary from 18.629 to 18.77, 15.690 to 15.738 and 39.188 to 39.435, respectively. The (87Sr/86Sr)i varies from 0.709215 to 0.710463，and (143Nd/144Nd)i varies from 0.512044 to 0.512093, with a calculated result of εNd(t) from -8.40 to -7.45 and TDM2from 1524 to 1602 Ma. On the basis of the results above, we can conclude that the quartz dioriteporphyrites should be Itype granite with typical feature of arc magmatism. The genesis can be attributed to the southward subduction of the BangongNujiang Ocean seafloor, which dehydrated and caused the partical melting of mantle wedge. The upwelling of mantle materials led to the partial melting of Mesoproterozoic lower crust and formed the magma of the Deneng quartz dioriteporphyrites.