Sinocyclocheilus gracilis can be diagnosed from all congeners with the exception of S. jii, S. guilinensis, S. yishanensis, S. huangtianensis and S. macrolepis by having an unossified last unbranched dorsal-fin ray and lacking serrations along its posterior margin (vs. ossified and with serrations posteriorly). It has significantly larger lateral line scales than those in the rows immediately above and the below the lateral line compared to S. macrolepis having nearly the same size; and has fewer lateral line scales (46-50) compared to 57-69 in S. yishanensis. It can be separated from S. jii, S. huangtianensis and S. guilinensis in having the following characters: body depth 21.0-23.8% SL (vs. 23.4-33.2); eye diameter 3.9-4.9% SL (vs. 5.7-8.6); 12 rakers on the first gill arch (vs. 6-11); black spots on the sides in life absent (vs. present). It further differs from S. guilinensis in having 21-23 scale rows above (vs. 19-20) and 14-15 scale rows below (vs. 11-12) the lateral line; from S. jii in having 12 rakers on first gill arch (vs. 6-7) and snout length 8.0-11.5% SL (vs. 6.5-7.7); and from S. huangtianensis in having 36-38 scales on lateral line (vs. 52-59) (Ref. 95535).