The diazonium salts of various substituted naphthol sulfonic acid couple with phenol-thiourea resin afforded novel oligomeric acid azo dyes. The novel oligomeric acid azo dyes show excellent dyeing properties on various textile fibers. They shows that the produced dye have powerful fixation properties. The dyes fixed on the fiber with nearly minor unemployed dye. The majority of the dyes have elevated fixation on textile at a lesser amount of exhaustion. While using these dyes commercially it may influence the environmental saving by a lesser amount of dye effluents from textiles.