Detailed zircon U-Pb age measurements were done on the Qinjia granite. These zircons have high Th/U ratio with zonal structure, which indicate magmatic zircons. The ziron U-Pb age for three granite rocks are 412.4±1.8Ma, 434.8±1.7Ma and 442.4±1.8Ma, respectively. The results show that all the granites formed in late Ordovician to early Silurian, which reflect the important stage of Caledonian magmatism, and provide a strong evidence for further understanding the Caledonian magmatism and its geodynamic process in South China.