A revision of the freshwater crab genus Hainanpotamon (Crustacea: Decapoda: Brachyura: Potamidae: Potamiscinae), with a redescription of Potamon (Potamon) orientale (Parisi, 1916) and descriptions of three new species.

The taxonomy of the potamid genus Hainanpotamon , from Vietnam, Laos, Hainan Island (China) and, purportedly, Okinawa Island (Japan) is reviewed. The type species, Potamon (Potamon) orientale (), is redescribed and a lectotype designated. In addition, three new species are described. The poorly known species Potamon (Geothelphusa) globosum , is assigned to Hainanpotamon and its taxonomy clarified, with a lectotype designated. A key to the nine species of Hainanpotamon is provided.