Xiagucheng granite, locates in the south margin of North Qilian Orogenic Belt(NQOB), mainly consists of quartz diorite and granodiorite. It is characterized by the mass fraction of SiO2（58.78% to 6953%）and Al2O3（14.30%~15.30%）,the value of A/CNK is 0.86~1.08.These characteristics indicate Xiagucheng granite belongs to metaluminous and/or weak peraluminous, calc alkaline high K calc alkaline I type granite. Overall, its geochemical compositions show low SiO2, high CaO, FeO(as total iron) and MgO. The total REE contents range from 87.22×10-6 to 150.54×10-6,and the ratio of LREE/HREE is between 6.24 and 11.11, corresponding to weak fraction. The enrichment of LILE（Rb, Th, U, Pb, La）and depletion of HSFE(Nb, Ta, P, Ti ) imply the granite mainly derived from partial melting of crust. Zircon LA ICP MS in situ Lu Hf isotope analysis results of εHf(t)=-5.7~-0.7 and tDM2=1.51~183Ga, suggest its source region maybe mainly Mesoproterozoic accretionary crustal material. LA ICP MS zircon U Pb analysis of quartz diorite yield a weigted mean age of 505.4±4.1Ma (MSWD=078, n=21), which is consistent with Kekeli granite (512Ma~501Ma) and Yemazui granite(~508Ma). Overall, Xiagucheng granite may formed in island arc environment of active continental margin and controlled by southward subduction of the North Qilian Ocean.