The granitic pegmatites of the North Qinling tectonic belt are important pegmatite areas in China. There are controversial about the formation age and petrogenesis of the granite pegmatite. This paper presents LA-ICP-MS zircon U-Pb age, Hf isotopic and geochemical data of the Xiahecun granitic pegmatites and the Shanghecun granitic pegmatites in the Guanpo area to determine the formation age, the magma source, the petrogenesis and tectonic setting. LA-ICP-MS zircon U-Pb dating suggests that the Xiahecun granitic pegmatites and the Shanghecun granitic pegmatites crystallized 360~361 Ma and 334.8 Ma, respectively. The Xiahecun granitic pegmatites and the Shanghecun granitic pegmatites contain garnet, muscovite and tourmaline, with high contents of SiO2, Na2O and K2O, and low contents of CaO, FeOt and MgO, and are mainly peraluminous. The Xiahecun granitic pegmatites and the Shanghecun granitic pegmatites show little fractionation between LREE and HREE, and have obvious positive Eu anomalies. The magma is enriched in large ion lithophile elements (LILE) such as Rb, Th, Ba and Cs, and depleted in high field strength elements (HFSE) such as Nb, Ta and Ti, with low Nb/Ta and Zr/Hf ratios, indicating a high degree of crystallization differentiation. The Xiahecun granitic pegmatite has low εHf values ranging from －11.7 to－6.2. Shanghecun granitic pegmatite εHf values rangs from －4.9 to 1.1, higher than that of Xiahecun granitic pegmatite. Based on this, the Xiahecun granitic pegmatite is the result of partial melting of the ancient crust, while the Shanghecun granitic pegmatite is the result of partial melting of the juvenile lower crust, and then magma assimilates and contaminate the wall rocks. The granitic pegmatite in the eastern part of North Qinling can be divided into northern rare metal granitic pegmatite and southern uranium granitic pegmatite.