Abstract: Through the petrography research of the Nenjiang-Heihe tectonic belt, the authors found a set of anatectic granite body in Kolo area of Nenjiang. From the point of macroscopic view, the rock is an anatectic intrusive body of atypical granite with metasomatic texture, taxitic structure, and augen structure. The authors tested the age of the anatectic granite using zircon LA - ICP - MS U - Pb dating, and obtained three groups of discordant U-Pb age, which were 390 Ma, 157~163 Ma and 113 Ma. The age of 113 Ma represents late metamorphic thermal event age and the age of 157~163 Ma means the age of protolith crystallization. Througn comprehensive analysis of the anatectic granite formation, the authors supposed that it was mainly related to the anatexis under the thermal effect of the deep ductile shear in Nenjiang-Heihe fault. The division and determination of the anatectic granite provide new data for deeper study of the Mesozoic activity of Nenjiang-Heihe fault.