Abstract:One new species, Rhododendron bainaense Xiang Chen & Cheng H. Yang from Guizhou Province, China is described and illustrated. Rhododendron bainaense is most similar to R. rubiginosum from which it differs mainly by having oblong to ovate leaf blades, subequal, amber and concave scales on leaf blades abaxial surfaces, a 2.5 cm long, pale pinkish white and spotless corolla, and nearly glabrous or partly puberulent filaments, and pale brown anthers. The new species is Critically endangered (CR), based on the IUCN Red List Categories and Criteria, since there is only one population that includes 3 mature individuals found so far during the field work, therefore, careful protection is highly desired.