The present invention provides a process for easily producing an alkylene oxide adduct to an aliphatic amine compound which has a fully excellent color, is not turbid, and does not deteriorate in color even through long-term storage. That is, the present invention provides a process for producing an alkylene oxide adduct to a primary or secondary amine compound having an aliphatic, saturated or unsaturated, hydrocarbon radical having 8 to 22 carbon atoms, having an excellent color, by reacting an alkyene oxide to the amine compound, characterized by comprising the step of adding a base or an aqueous solution thereof to the amine compound and then heating the mixture.