Triplophysa yajiangensis sp. nov. is described from the upper and middle reaches of the Yalong River, Yangtze Basin, Ganzi Prefecture, Sichuan Province, China. This new species can be distinguished from other congeneric species by the following characters: body surface smooth and scaleless; lateral line complete; caudal peduncle compressed and tapered slightly; lower jaw shovel-shaped; head shorter than caudal peduncle; dorsal-fin origin anterior to pelvic-fin origin and closer to tip of snout than to caudal-fin base, last unbranched ray hard; pelvic-fin reaches or exceeds anus; posterior chamber of gas bladder absent; intestine spiral type with 3-5 winding coils.
Keywords: China; Cypriniformes; Nemacheilidae; New species; Sichuan Province; Triplophysa yajiangensis.