Abstract: The Shuikoujing alkaline complex, the largest basic-ultrabasic complex exposed in the southern Panxi Rift. Previous studies suggest that the complex is closely related to the Late Permian Emeishan Large Igneous Province (ELIP) magmatic activity, but precise geochronological constraints have been lacking, which has hindered the understanding of the genesis, evolution, and tectono-dynamic background of the alkaline complex in the southern Panxi rift. In this study, based on detailed petrographic and geochemical investigations, using LA-(MC)-ICP-MS analytical techniques to conduct U-Pb dating, trace element composition, and Sr isotopic analysis on apatite from various lithologies. These analyses aim to explore the genesis, evolution, and the associated tectono-dynamic background of the complex. The results show that the U-Pb ages of apatite from the gabbro and pyroxene diorite are 263±11 Ma and 262.8±6.4 Ma, The in situ Sr isotope composition of apatite is uniform (0.7041~0.7045) and exhibits typical mantle-derived characteristics. Suggesting that the formation of the primary magma is closely related to the activity of the ELIP, originating from low-degree partial melting of the lithospheric mantle in an intraplate extensional setting, and subsequently underwent rapid magmatic differentiation and evolution. Additionally, these alkaline complexes in the southern Panxi Rift are inferred to be products of the initial magmatic evolution of the ELIP.