Abstract: Objective  To investigate the species of freshwater crabs in Fujian Province, China.  Methods  Fresh-water crabs were collected in Pingtan County of Fujian Province. The morphological characteristics of the crabs and the habitats were observed. The crab morphology was described and crabs examined for the presence of Paragonimus metacerariae.  Results  A new species of freshwater crabs named Nanhaipotamon pingtanense sp. nov. was obtained, holotype（FJ6133，1）:♂, carapace length 36.1 mm, breadth 46.8 mm, thickness 26.7 mm; allotype （FJ6133，2）:♀, carapace length 33.9 mm, breadth 42.7 mm, thickness 25.4 mm, collected from Pingtan County（N 26°52.958′；E 119°58.722′, and 16-47 m above sea lever）. Distal segment of the first male pleopod with squarish-rounded inner-distal angle, and the comparatively stout out-distal angle’s end narrowed. The out-lateral border sloped downwards, concave situated in the middle. The segment length is 2.3 times as long as the subdistal segment. This species usually lived in the ditch and hid in mud hole. Paragonimus metacercariae were not found.  Conclusion  A new species of Nanhaipotamon collected from Pingtan County of Fujian Province were described, and named as Nanhaipotamon pingtanense.

Key words: Decapoda, Nanhaipotamon, New species, Fujian