Abstract: With study on the geochemistry and zircon U-Pb isotopic geochronology of the miarolitic granites in middle Daxinganling Mountains, the age, petrogenesis and tectonic implication are discussed. The zircons from the miarolitic granites show oscillatory growth zonation and high Th/U ratios, indicating a magmatic origin. The LA-ICP-MS U-Pb age of 113.1~11.1 Ma suggests that the rock was formed in the late stage of Early Cretaceous. The granites are characterized by high SiO₂ and rich alkali, with negative Eu anomaly and weak peraluminous. The trace elements are enriched in Rb, Th, La, Zr and Hf and depleted in Ba, Sr, P and Ti. It is concluded that the miarolitic granites belong to highly fractionated I-type, formed in a post-collisional extensional setting after the convergence of North China, Siberian, North American and Pacific plates.