Geochemical analysis and zircon LA-ICP-MS U-Pb dating for the Fangfan granites from two granitic bodies in western Dabie Mountains were conducted in this study. The geochemical characteristics of biotite granite and quartz syenite are generally similar, characterized by high SiO2 (ave.77.2%), peraluminous (A/CNK value between 1.03～ 1.13), alkalinity ratio (AR value between 5.43～7.23). REE analysis show that granites have an average ΣREE content of 62.4×10-6, an average (Ce/Yb)N of 0.67, an average (La/Yb)N of 0.97 and an average δEu of 0~20, an average Ga/Al of 3.16 and an average Zr Nb Ce Y of 578 The chondirte-normalized REE pattern displays flat curves. The large ion lithophile elements, such as Rb, Th, U, K are relatively enriched, whereas high HFSE such as Nb, Ta, Sr and Ti are relatively depleted, which indicate residual plagioclase in the granite source area. Temperatures of zircon saturation and REE saturation concentration are around 833～877℃ and 773～862℃ respectively, indicating a high initial temperature of initial magma. These characteristics show that the Fangfan granites are typical of A-type granite formed in the intraplate extensional setting of middle-upper crust. LA-ICP-MS U-Pb dating analysis for zircons from two types of samples yielded an age of 773.0±1.6 Ma (MSWD=0.96, n=33) for biotite granite and 7598±23 Ma (MSWD=1.6, n=28) for quarz syenite, indicating they formed in a tectonic background of Neoproterozoic ocean-continent subduction in the Nothern Yangtze block and was probably the product of magmatism of continental marginal arc. The Fangfan granites, which formed earlier than that of their wall rocks, is the transformed m lange belt by late tectonic, with its magmatism no direct relation with copper mineralization.