Sweltsa is a genus of green stoneflies in the family Chloroperlidae and is distributed throughout the Nearctic and East Palaearctic Regions. As they are sensitive to pollutants, they are often used as an indicator species for determining the quality of water bodies. There are around 57 species of this genus worldwide and 11 of those have been identified from China. A new species of the Alloperlini genus Sweltsa Ricker, 1943, Sweltsa ligula Rehman, Huo & Du sp. n. is described from Kuankuoshui National Natural Reserve, Suiyang County, Guizhou Province, southwest China. This is the first report of the family Chloroperlidae from Guizhou Province. Diagnosis, description of male, female and nymph, illustration of terminalia and similarities with closely-related species are provided and discussed.