PURPOSE: To provide the titled compsn. having a high concentration and exhibiting excellent dispersibility at an elevated temp., by finely dividing a dye cake in an aq. medium contg. a specified anionic surfactant and uniformly dispersing it.

CONSTITUTION: Creosote oil (or its fraction) is sulfonated with sulfuric acid. A given amount of fresh creosote oil is added to the sulfonated product. An aliph. aldehyde in an amount of 0.5W1 time by mol is added thereto. The mixture is condensed at 100°C under sulfuric acidic conditions and neutralized with calcium carbonate. The resulting condensate salt having sulfonic groups in an amount of 2.7W3.4mmol/g is used as an anionic surfactant. A dye cake is crushed in the presence of said anionic surfactant in an aq. medium by using a sand grinder to disperse the dye in the medium, thus obtaining a disperse dye compsn.