Objectives: There are large-scale Early Cretaceous magmatite from east to west Gangdese belt. Different scholars have diverse view on the causes of its formation. Tajilixialong granodiorite is located in the west part of Gangdese tectonic magmatite belt, middle—western Lhasa block. This paper reports whole-rock geochemistry, zircon U-Pb age of Tajilixialong early Cretaceous granodiorite. Methods:A total of 4 granodiorite samples were collected in the study area, numbered as BN8201-1, BN6156-1, BN6157-1, BN4101-DY. BN6156-1, BN8201-1 are both geochemistry sample and LA-ICP-MS sample, while BN4101-DY, BN6157-1 are just geochemistry sample (3 other geochemistry data was cited). Zircon U-Pb isotope analysis was completed by Agilent 7500a ICP-MS instrument at the State Key Laboratory of ore deposit geochemistry, Institute of Geochemistry, Chinese Academy of Sciences. The diameter of analysis laser beam is 30μm. Standard zircon 91500 (age 1064Ma) and GJ1 (age 600Ma) are used as external calibration, NIST SRM 610 29Si as internal calibration. The standard error is 1Sigma. We used ICP MS Data Cal 9.2 software to analyze the data, Isoplot to calculate the weighted average age and draw U-Pb concordia ages graph. 4 geochemical samples were completed by the Southwest Metallurgical Geology Test Institute. The PHILLIPSPW-2404 X-ray fluorescence spectrometer was used to measure the principal component, its accuracy was better than 1%. Trace elements and REE elements were determined by ELEMENT-2 MS, which was better than 2% in accuracy. Results:Geochemistry analysis shows that: the rock is w(SiO2)=63.38%～72.56%, w(Al2O3)=13.85%～15.73%, Alk(K2O+Na2O)=5.12%～6.79%, w(K2O)/w(Na2O)=0.67～1.32, A/CNK=0.90～1.02. These features indicate that the rock belongs to weakly peraluminous calcalkaline type I series. Total REE content varies from 128.34×10-6～167.25×10-6, LREE/HREE=6.94～10.73, which shows enrichment of LREE and loss of HREE. The REE patterns is right-dipping. δEu=0.69～0.86 indicates that the rock has weak negative Eu anomaly. The rock is characterized by enrichment of Rb, Th, K and other LILE, and loss of Ba, U, Nb, P and etc. HFSE. Zircon U-Pb dating results show that Tajilixialong granodiorite mainly intruded at 126.3±1.1Ma, which belongs to the late Early Cretaceous.  Conclusions:The rock characteristic of enrichment of LILE and loss of HFSE shows the rock is island arc-volcanic affinity. Tajilixialong granodiorite mainly intruded at 126.3±1.1Ma, this is consistent with the large-scale Cretaceous magmatism era of Lhasa block. The rock has strong fractionation between LREE and HREE, enriched in Rb, Th, K, Zr, Hf and depleted in Ba, U, Nb, Sr, P, Ti. These features are the effect of island arc magmatism. The rock-magma may originated from partial melting of ancient lower crust, and mixed with mantle derived magma. The weak negative Eu anomaly of rock indicates that the magma source region may also exist plagioclase residual phase. The genesis of Tajilixialong granodiorite can be attribute to southward subduction of Bangong Co—Nujiang River oceanic seafloor and plate rotary afterwards. Mixed magma upwelled along the plate tectonic window, intruded, subsequent formed the Tajilixialong granodiorite.