Rhodeus flaviventris, a new species, is described from the Le-An River, a tributary flowing into Poyang Lake in the Yangtze River basin, in Jiangxi Province, China. It is distinguished from all congeners by the combination of characters: branched dorsal-fin rays 9 (9-10); branched anal-fin rays 9 (9-10); longest simple rays of dorsal and anal fins thick and stiff; longitudinal scale series 33-34; transverse scale series 11 (10-12); pored scales 4-7; vertebrae 32-34; spindle-shaped eggs with major axis of 3.1-3.7 mm; color pattern of nuptial males (iris yellowish, belly yellow, central part of caudal fin orange, dorsal and anal fins with reddish-orange stripe).
Keywords: Pisces, Yangtze River, taxonomy, breeding season, egg development, ovipositor length.