The giant Xikuangshan deposit, located in central Hunan, is the largest antimony deposit in the world, and is titled as Capital of Antimony. Lamprophyre is the only igneous rocks in the Xikuangshan district. In this paper, we use petrological and geochemical data to constrain nature of the mantle source, petrogenesis and tectonic setting of the lamprophyres, as well as its relations with the antimony mineralization in the Xikuangshan deposit. The lamprophyre in this study is calc-alkaline rocks. They have high TiO2, and low Al2O, and MgO. They are characterized by enrichment of LILE and LREE and depletion of HFSE. They also have high (Sr-87/Sr-86)(i) ratios and low epsilon(Nd)(t) values. These geochemical features are similar to the melts derived from EM2-type mantle source. The rocks experienced fractional crystallization of olivine and plagioclase without significant crustal contamination during their emplacement. Therefore, parental magma of the lamprophyres was probably derived from the phlogopite-bearing lherzolite in garnet stability field; the ancient lithospheric mantle was variably metasomatized by hydrous fluids from subducted oceanic sediments. The magmas quickly emplaced along the extensional fault in the rift setting during the Cretaceous. There is no genetic relationship between the magmatism and the antimony mineralization in the Xikuangshan district.