The Shuangjianzishan deposit, which is located in the southern Great Xing’an Range, is a super- large silver polymetallic deposit newly discovered in Bairin Left Banner, Inner Mongolia, China in recent years. The formation age, material source and its relationship with mineralization of the altered porphyry close to ore veins in the mining area have attracted the attention of previous scholars.Methods:A comprehensive study of single- grain zircon LA- ICP- MS U- Pb dating and Lu- Hf isotope was conducted for the altered granodiorite porphyry close to ore veins in this paper. Results：The results show that the altered granodiorite porphyry was formed at 248.3±1.2 Ma and is a product of Early Triassic magmatism. In situ zircon Lu- Hf isotope analysis shows that the n(176Hf)/177n(Hf) ratio and εHf(t) values of the Early Triassic granodiorite porphyry range from 0.282805 to 0.282993452 and 6.3 to 12.9, respectively. The peak age of zircon Hf isotope two- stage model age (TDM2) is concentrated between 528 Ma and 631 Ma.Conclusions：The altered granodiorite porphyry close to ore veins intrusion was formed significantly earlier than mineralization, which also indicates that there is no direct genetic link between mineralization and Early Triassic magmatism. The intrusion was generated from depleted- mantle or juvenile- crust.