Zircon LA-MC-ICP-MS U-Pb analysis was carried out for the Xitian granite in east Hunan Province. Two samples from the first period of medium-(fine) grained porphyritic biotite monzonitic granite show ages of (220.9±0.6) Ma and (220.7±0.7) Ma, respectively. The results show that the Xitian granite is a product from partial melting of Proterozoic crust materials of Cathaysian block under the extensional setting. The confirmation of Xitian A-type granite has important significance for understanding the tectonic background of the east part of Hunan Province during Indosinian and Yanshanian movements. It also provides more evidence that there is W-Sn mineralization related to A-type granite during Indosinian period in South China.