The Wuyi intrusion, located in the Da Hinggan Mountains, is mainly composed of orthogranite and alkali feldspar granite. Chronological and geochemical studies of the Wuyi intrusion was carried out in order to constrain their petrogenesis. Zircons from the intrusion display oscillatory zoning and high Th/U ratios (0.43 to 0.57), implying its magmatic origin. Zircon SHRIMP U-Pb dating of the Wuyi intrusion indicates that it was formed in early Permian with the age of 299Ma±3Ma. Its SiO2 and K2O content range from 77.63% to 81.83% and 3.64% to 5.1%, respectively, the K2O+Na2O and the A.R are in the range of 6.43% to 8.02% and 3.18 to 3.62. Moreover, the Wuyi intrusion is enriched with light rare earth dements as well as Th, Nd, Rb and K but markedly depleted in Ba, St, P and Ti. It is inferred that the Wuyi intrusion belongs to post-orogenic Ⅰ-type granite formed in an extensional tectonic setting.