Abstract：Isotopic age and geochemical characteristics of the potassic lamprophyre in Linxiang area of northeast Hunan were analyzed in this paper. Its whole-rock 40Ar/39Ar plateau age is (119.5±2.2)Ma, indicating a product of Early Cretaceous. The lamprophyre belongs to the alkaline series and is of potassic-superpotassic nature, with rich large-ion lithophile elements (LILE) and high field-strength elements (HFSE), right oblique chondrite-normalized REE pattern, clear low TDMⅡ value of 1.5Ga and low εNd（t）value of -7.3. These characteristics suggest that the lamprophyre was derived from anomalous (metasomatic enriched) mantle, and was formed in a post-orogenic tectonic setting characterized by lithospheric extension and thinning.