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The Ailaoshan-Jinshajiang porphyry belt located in the Sanjiang area of eastern Tibetan Plateau is one of the major polymetallic metallogenic belts in China. However, the nature and genesis of magmatic intrusions associated with the porphyry copper mineralization in this belt remain contentious. Here we focus on the Bijiashan Deposit, one of the large-scale porphyry copper deposits in this area, to gain insights on the host rock, petrogenetic mechanism, tectonic setting based on geochemistry, zircon U Pb geochronology and Lu Hf isotopic compositions. Zircon U Pb dating of the ore-hosting porphyry yielded an age of 35.6 ± 0.2 Ma. The major elements of the porphyry show wide range in SiO2 (58.33–70%), high K2O (2.83–8.85%) and Na2O + K2O (mostly>8%), and moderate range in A/CNK (0.56–1.17). Our data suggest that the porphyry belongs to high-Kcalc-alkaline-alkaline and metaluminous-peraluminous series. The trace elements are characterized by enrichment in K, Rb, Ba, La and Nd, but depletion in Ta, Nb, P and Ti, and enrichment in LREE but depletion in HREE with LREE/HREE of 9.78–20.10. The main intrusion associated with mineralization corresponds to alkali-richA-type granitoid, with high TFeO (0.49–3.4%), low Na2O/K2O (0.23–1.62), and high 1000*Ga/Al (2.17–2.64 except 1.57), and right-declinedREE patterns. However, some of the geochemical features also are consitent with the typical characteristics of C-adakite rocks, including high contents of Al2O3 (13.49–16.12%) and Sr (>400 ppm), lower MgO (mostly