Xiurenbagrus dorsalis can be diagnosed from its congeners by the following combination of characters: 7 dorsal-fin branched rays (vs. 6 in X. xiurenensis and X. gigas); pelvic-fin origin opposite base of fourth branched dorsal-fin ray (pelvic-fin insertion posterior to dorsal-fin base in X. xiurenensis and X. gigas); serrations absent on the posterior edge of pectoral-fin spine (vs. strong serrations present in X. xiurenensis and X. gigas); adipose fin confluent with caudal fin (vs. adipose fin posteriorly with a free flap and not confluent with caudal fin in X. xiurenensis and X. gigas); maxillary barbel longer than head length and reaching posterior tip of pectoral-fin (vs. maxillary barbel shorter than head length, reaching or slightly exceed pectoral-fin insertion in X. xiurenensis and X. gigas); eyes absent (vs. small eyes present in X. xiurenensis and X. gigas) (Ref. 96642).