A new species of Colocasia Schott, C. lihengiae C. L. Long et K. M. Liu, sp. nov., is described and illustrated. The species is restricted to the rainforest of Xishuangbanna in southern Yunnan, China. Diagnostic morphological characters that distinguish the new species from the related species, C. fallax Schott, are discussed. Chromosome numbers (2n=28) were observed in plants of C. lihengiae cultivated at the Kunming Botanical Garden.