Three new crustacean species of the order Tanaidacea are described from the South China Sea. Alloleptochelia falciformes sp. nov. (Family Leptocheliidae) can be distinguished from the most similar species, A. evansi (Edgar, 2012), by the much stouter body, and fewer articles on the antennule flagellum and relatively longer pereopods 46 dactylus of the male. Kalloleptochelia multiarticulata sp. nov. (Family Leptocheliidae) can be easily differentiated from its congeners by the male having significantly more antennule flagellum articles, a two-articled uropod exopod, one additional dorsal seta on the pereopods 23 merus, and one additional spiniform seta on the pereopod-6 carpus. Paranesotanais incisus sp. nov. (Family Nototanaidae) differs from its only congener, P. longicephalus Larsen & Shimomura, 2008, by the female having one robust inner seta on the palm of the cheliped propodus, and the male having one long and conspicuous notch extending from the outer surface to the ventrodistal corner on the cheliped carpus. Morphological keys and comparison tables of all known species of the genera Alloleptochelia and Kalloleptochelia, as well as a key of the genus Paranesotanais, are provided.