Abstract: The Taohuashan and Xiaomoshan granites occur in Huarong county，Northeastern Hunan Province, and intruded into the Mesoproterozoic Lengjiaxi Group. Using the method of single zircon LA-ICP-MS U-Pb dating, the emplacement ages of 129 ± 1 Ma and 117 ± 1 Ma were yielded for these two plutons. The main rock type of Taohuashan pluton is (gneissic) two-mica monzonitic granite，with SiO2 = 71.75~73.81%，K2O/Na2O = 0.84~1.11，and belonging to weak peraluminous high K calc-alkaline series. It is obvious that the Taohuashan rocks are enriched in LILE and depleted in HFSE; with moderately negatively Eu anomalies, relatively high ΣREE contents, Rb/Sr = 0.9~2.7，（La/Yb)N = 26.92~86.02, high ISr (0.714~0.723），low εNd (-9.76 ~ -10.6）, and high t2DM (1.72~1.79Ga）. The rock type of Xiaomoshan pluton is biotite monzonitic granite. SiO2=69.64~72.73%，K2O/Na2O = 0.62~0.7，metaluminous to weakly peraluminous，Rb/Sr = 0.26~0.88，（La/Yb)N = 11.97~12.67,low ISr (0.707~0.709），high εNd (-6.38~-6.73）， and low t2DM (1.43~1.46 Ga）. The analysis shows that the Taohuashan two mica monzonitic granite is crustal-derived CPG. Its source rocks are the Palaeo-Proterozoic basement of south China. The Xiaomoshan biotite monzonitic granite is similar with CPG type, with low maturity metagreywackes as its source rocks. The Taohuashan and Xiaomoshan plutons were formed in a local compressional environment under the extensional geological setting of South China. The thrust of Jiangnan Fault caused a small scope of crust thickening in Huarong region, and provided a fluid accumulation channel for the wet anatexis of Taohuashan source rocks. The formation of Xiaomoshan pluton is related to magmatic underplating. The hot mantle magma not only provided heat for the partial melting of crust, but also caused magma mixing with the crustalderived melts.