The Zhangpu composite granite pluton, with an outcrop area over 1 500 km², is located in the coastal region of southeast Fujian Province. It is a big batholith formed by multi-stage magmatisms. According to the lithological characteristics, this pluton can be divided into three intrusions: the Changqiao (CQ) biotite granite, the Chengxi (CX) alkali-feldspar granite and the Huxi (HX)  granodiorite. Zircon U-Pb ages obtained by LA-ICP-MS for the three intrusions are 119 Ma, 101 Ma and 96 Ma, respectively. Based on a synthesis of petrography, geochronology, elemental and isotopic geochemistry,  it is suggested that the granites in all three intrusions were most likely generated via a two-stage process including formation of parental magma by mixing of mantle-derived magma and induced crustal-melted felsic magma in the deep crust, and then underwent variable degrees of differentiation during magma ascent.