Based on a field survey, the authors investigated the rock formation time of Lujing by SHRIMP zircon U-Pb dating, and determined its age as 132.0 Ma (range in 128.7～135.4 Ma). Meanwhile, early xenocryst of 1 945 Ma old was found, which indicates that there is a Palaeoproterozoic basement in the South Jiangxi area.Firstly, this result revises the previous determination of the Lujing kimberlite-like rock as Caenozoic by K-Ar and Rb-Sr dating method, and provides new correct data for investigating the evolutionary history of tectonic structures of the South Jiangxi area. Secondly, this result indicates that the transformation of the tectonic system in the late Yanshanian period is related to the interaction of crust and mantle, and the magma of the Lujing kimberlite-like rock may have originated from enriched mantle.