Based on petrology, zircon U- Pb chronology and geochemistry, this article discusses the genesis, material source and tectonic background of tianxiangou quartz monzonite porphyry in central section of Great Hinggan Mountains. According to zircon LA- ICPMS U- Pb dating method, the age of Tianxiangou quartz monzonite porphyry is 124. 4 ± 1. 0 Ma and the age is Early Cretaceous. Tianxiangou quartz monzonite porphyry belongs to alkaline and quasi aluminous rocks with Rittman index σ= 3. 86 ~ 5. 1, total alkali (Na2O + K2O) =9. 14% ~ 10. 35%, K2O / Na2O = 0. 93 ~ 1. 0, A/CNK=0. 76 ~ 0. 93, and the genetic type is I- type granite. The rocks are rich in large ion lithophile elements such as La, Ba, Ce and U, and relatively deficient in high field strength elements such as Hf and Zr; (La/Yb)N=11. 72 ~ 13. 90, with obvious fractionation, enrichment of light rare earths, loss of heavy rare earths, negative Nb and Ta anomalies, showing the geochemical characteristics of island arc granites. δ Eu=1. 00～1. 59. \[n (87Sr) /n (86Sr)\]i=0. 705065, ε Nd (t) =1. 93, the source area may be the upper mantle. Combined with the Mesozoic crustal evolution background in the Great Hinggan Mountains, it is considered that the Tianxiangou quartz monzonite porphyry was formed in a volcanic arc environment related to the subduction of the oceanic crust, the regional stress field was transformed from compression to extension, and the magma source was the upper mantle.