Liquid-liquid system (LLS) for separation of chemical mixtures into their comtituents is of central importance in the chemical industry.Limited by mass transfer between two phases,liqnid-liquid extraction is impossible to produce more than two products in a single step.By comparison,three-liquid-phase system (TLPS) comisting of three macroscopically immiscible liquid phases has more spatial locations and shows an extended separation capacity.A TLPS can be developed by creating a second phase and a third phase in the homogeneous feed solution with suitable phase-forming substances under appropriate conditions [1,2].