The solubilities of taurine (2-aminoethanesulfonic acid (H2NCH2CH2SO3H)) and sodium sulfate in a series of room temperature ionic liquids were examined, and a novel and greener separation method combined with chlorinated dialkylimidazolium ionic liquid as leaching reagent and organic solvent as precipitating reagent was developed. Using such process, selective separation of taurine from solid mixture containing large amount of sodium sulfate could be realized with 67-98.5% of single separation yield. The recycling of ionic liquid and organic solvent used in this separation process is possible. (C) 2003 Elsevier B.V. All rights reserved.