Maixie pluton is composed predominantly of lightgray, fineto mediumgrained, equigranular biotite granodiorite. LAICPMS zircon UPb dating yielded two weighted mean 206Pb/238U ages of 4334±71 Ma (MSWD=082) and 4318±60 Ma (MSWD=043) for the Maixie pluton, indicating that it was the product of magmatic activities in the Early Paleozoic. The Maixie granodiorites contain minor amount of amphiboles. Geochemical analysis shows that the pluton is characterized by high SiO2(620%~7143%) and high K2O/Na2O(088~242) (with a total alkali (K2O+Na2O)=539%~812%), and low Fe2O3(261%~570%), MgO(096%~290%), CaO(139%~511%), TiO2(027%~067%) and P2O5(006%~010%), with weak peraluminium (A/CNK=098~125, with an average value of 108). There exists a clear negative correlation between SiO2 and P2O5. All these features suggest that the Maixie granodiorites belong to highK calcalkaline Itype granite. The trace element studies show an enrichment of Rb, Th, LREE and depletion of Nb, Ta, Ti, P, Ba, Sr and other elements, with distinct LREE and HREE fractionation of (La/Yb)N=500~4042 (a mean of 1697) and weak to medium Eu negative anomalies of δEu=063~〖JP2〗100 (an average of 077). Homogeneous SrNd isotopic compositions {(87Sr/86Sr)i〖JP〗=0708667~0709175, εNd(t)=-757~-729, TDM2=175~187Ga (a mean of 181Ga)}, relatively high (87Sr/86Sr)I ratios and negative εNd(t) values with twostage Nd mode ages of Paleoproterozoic suggest that the Maixie granodiroites generated by partial melting of the Paleoproterozoic crust. Experimental petrology and geochemical characteristics of our studied samples show that the Maixie biotite granodiorites resulted from waterunsaturated partial melting of the intermediatemafic rocks (e.g, amphibolite) in the lowerto middlecrust, with addition of a certain content of mantlederived materials at the initial stage of magmas, and extensive fractional crystallization of amphibole, biotite, ilmenite, titanite, plagioclase and apatite. The mantlederived materials were the product of partial melting of the Paleoproterozoic subductionmodified lithospheric mantle in South China. Combined with regional geological background and published data, this study suggests that that the Maixie pluton was formed in a postcollisional introcontinental environment, and partial melting of early Paleozoic early Paleozoic lower crust in South China due to underplating of mantlederived magmas resulted in extensive distribution of intracontinental magmatic rocks.