According to the present invention, a process is provided for producing an acyl group-containing composition that includes a step of reacting a long chain N-acyl acidic amino acid anhydride with one or more compounds which have, per molecule, m functional groups of one kind or more selected from the group consisting of hydroxyl, amino and thiol groups in an aqueous solvent and/or a mixed solvent of water and an organic solvent (reaction step). The process makes it possible to produce an acyl group-containing composition that is free from coloration under moderate conditions.