Two new species, Rhododendron dayaoshanense L. M. Gao & D. Z. Li from Guangxi, southern China, and Rhododendron longilobum L. M. Gao & D. Z. Li from Yunnan, southwestern China, are described and illustrated here. Rhododendron dayaoshanense, known only from Dayaoshan Mountain, Guangxi, is distinguished by the following characters: the leaves narrowly oblanceolate or oblong-lanceolate, short setose on undersurface and midrib, petiole densely glandular setose, pedicel densely gray-puberulent and glandular-pilose as well as ovary densely flavescent-tomentose. Rhododendron longilobum is collected only from Daweishan Mountain, southeast Yunnan, and is distinguished from its close relatives by the characters of the leaf blades with prominent lateral primary veins on both surfaces, calyx lobes membranaceous, linear, linear-lingulate or narrowly triangular, and 0.5-2 car long; ovary densely flavescent tomentose and truncate at the apex.