In this study，we carried out a comprehensive research using zircon U Pb dating，petrogeochemistry and Sr Nd Pb Hf isotope analysis on the Xinxian granitic batholith to investigate its age, petrogensis, rock source and geochemical dynamic background. Analysis shows that the Xinxian granitic batholith has a zircon 238U 206Pb age of 125.5±1.5 Ma. Whole rock chemical compositions are characterized by high silica and alkali contents, lower values in Mg, Fe and Ca. The granites are enriched in light REE and large ion lithophile elements (Rb, K, Th, U) and Pb, but depleted in heavy REE, high field strength elements (Nb, Ta, and Ti ), Sr, and Ba. Isotopic analyses of the Xinxian granitic batholith yieldedinitial Sr ratios (87Sr/86Sr)i ranging from 0.706949 to 0.707086, low initial Pb isotopic ratios ［(206Pb/204Pb)i=16.611~17.152，(207Pb/204Pb)i=15.304~15.432，(208Pb/204Pb)i=37.316~38.702］, as well as low εNd(t) values (-13.65 ~ -13.51) and old Nd model ages (tDM2=2.12~2.13 Ga). Zircon has low εHf(t) values (-22.92~ -19.40) and old Hf model ages (tDM2=2.39~2.61 Ga). Based on the results of the whole rock geochemistry, geochronology and isotopic compositions, it can be concluded that the Xinxian granitic batholith belongs to a high K calc alkaline fractionated I type granite, which resulted from partial melting of the lower crust of Yangtze Block which probably consists of Neoproterozoic TTG like magmatic rocks at the northern margin of the Yangtze Block under a non thickened lower crust setting (<35 km).