The Tinggong porphyry Cu—Mo deposit is one of the first explored deposits in Tibet. Ore bearing biotite granodiorite, coarse grain monzogranite and fine grain K feldspar grantie are spread within this area and detailed studies of above major granites are benefited for future exploration. LA ICP MS zircon U Pb dating, major and trace elements, Rb Sr, Sm Nd, Pb isotope composition were test by this study. The results show that the age of above granites are 50.32 Ma, 48.34 Ma, and 49.41 Ma, respectively, which are apparently older than that of mineralization. Above stocks belong to high K calc alkaline, weakly peraluminous, I type granites. The REE patterns indicate a LREE rich, with weak/no HREE fractionation V type model and strong depleted δEu, which are reverse with SiO2 content. All granites are rich in Th, U, K, Cs, and Rb, depleted in Ba, Nb, Sr, Ti. Whole rock Pb isotopic compositions show that calculated n(206Pb)/n(204Pb) n(207Pb)/n(204Pb), n(208Pb)/n(204Pb) are 18.414~18.5137, 15.616~15.7039, 38.6394~39.0029, respectively, indicating a high radio Pb isotope composition. Calculated n(87Sr)/n(86Sr) and n(143Nd)/n(144Nd) restrict in narrow range: 0.70320~0.70477, 0.51260~0.51265, respectively, with calculated positive εNd(t) (0.51~1.44). The above results indicate that spread magna are not related to the mineralization and derived from new lower crust/ depleted mantle during the roll back and break off of northward subducted ocean crust, undergoing AFC process during emplace.