Abstract: Abstract：The sedimentary evolution of the Late Paleozoic Youjiang basin is dealt with on the basis of the study of the sedimentary characteristics of the Late Paleozoic deep-water sedimentary strata, basalt geochemistry and important tectonic events of the sections at Badu of Tianlin, Pohe of Napo and Pingxu and Yangyu of Baise. The authors suggest that after the continental-margin rifting and separation in the late Early Devonian, the Youjiang basin underwent a complete evolutionary sequence from the formation stage of a rift basin (late Early-early Late Devonian), formation stage of an oceanic basin (Late Devonian-Early Carboniferous), strong spreading stage of the oceanic basin (Late Carboniferous-Middle Permian), contraction stage of the oceanic basin (Late Permian-early Middle Triassic), closing and rapid filling stage of the oceanic basin (late Middle Triassic).