Impatiens macrantha S. X. Yu & Ying Qin (Balsaminaceae), a new species from Guangxi, China, is described and illustrated. Phylogenetic analysis based on molecular data shows the new species to belong to I. subg. Clavicarpa and to be closely related to I. tubulosa with which it shares succulent stems and racemose inflorescences, but it can be easily distinguished by having a 4 – or 5 – ridged stem, obovate or elliptic leaf blade, and saccate lower sepal. Furthermore, I. macrantha is distinguishable from other Impatiens in China by its obviously larger leaves and flowers. The evidence from morphology and molecular data both support I. macrantha as new to science.