Impatiens rupestris K. M. Liu & X. Z. Cai, a new species of Balsaminaceae from Hunan Province in southern China, is described and illustrated. An identification key to the new species and its relatives is provided. Impatiens rupestris differs from I. polyneura K. M. Liu in its lamina base widely cuneate or ± rounded, the lateral veins in 11 to 16 pairs, the dorsal petal widely obovate, and the lower lobes of the lateral united petals connate into obovate lamella. It is distinct from I. obesa Hooker f. in its lamina elliptic or ovate-oblong, lateral united petals stipitate, upper corolla lobes widely obovate or suborbicular, lower corolla lobes connate into obovate lamella, and seeds with tuberculate testa.