PURPOSE: To reduce the amount of sodium sulfide to be used, suppress the formation of hydrogen sulfide and obtain the titled compound useful as an intermediate for agricultural chemicals and medicines, etc. without side reactions, by reacting a halogenated ethylamine hydrohalide with sodium sulfide in the presence of a caustic alkali.

CONSTITUTION: A halogenated ethylamine hydrohalide, e.g. chloroethylamine acetate, is reacted with sodium sulfide in the presence of a caustic alkali, e.g. NaOH or KOH, to give bis(2-aminoethyl)sulfide. Sodium sulfide.nonahydrate as the above-mentioned sodium sulfide is used in an amount of almost equivalent amount, preferably 1.0W1.1 equivalents based on the halogenated ethylamine hydrohalide. Water is used as a reaction solvent, and the temperature is within 20W100°C range.