The Mengya’a Pb-Zn deposit with lots of granite porphyries developing is located in the eastern section of the Gangdese Pb-Zn metallogenic belt. On the basis of study on LA-ICP-MS zircon U-Pb dating, geochemistry, and Hf isotopes of the granite porphyry, the emplacement sequence, petrogenesis, sources of diagenetic materials, and the relation between the Pb-Zn mineralization and granite porphyry have been discussed. Zircon U-Pb geochronology results show that the granite porphyries were formed during 13.18 to 13.57 Ma, and they were formed during the same stage of magmatism of the Miocene. Major elements of the granite porphyries have characteristics of enrichment in silicon and alkali and the parameter of A/CNK ranges from 1.04 to 1.15. Rare earth elements have the pattern of light REE enrichment with strong negative Eu abnormality. Rare elements compositions show that granite porphyries are rich in LILE such as Rb, Th, U, K and Pb and poor in Ba, Sr and the HFSE such as Nb, Ta, Ce, P, Zr and Ti. Geochemistry results show granite porphyries in the Mengya’a deposit are highly fractionated S type granite. εHf(t) values and two-stage model ages of zircons are -9.0~1.6 and 996~1673Ma respectively, with the average values of -2.0 and 1225Ma, which indicates that the magma sources of the granite porphyries in the Mengya’a deposit were from the remelting of the Nyainqentanglha Group basement.