The new working fluid was selected the water-lithium bromide-lithium nitrate-lithium chloride-Ethanol amine System. mole ratio of LiBr-LiNO₃03-LiCl is 5 : 1 : 2. And surfactant as like Ethanol amine was added 5wt% of total amount. The solubility data were obtained in the temperature range 253.15K ∼363.15K. The vapor pressure data were correlated as an Antoine-type equation. Duhring charts were constructed through the measurements of solubility and vapor pressure. Thus the operation range of this system were found to be broadened. Heat Capacity of water-lithium bromide-lithium nitrate-lithium chloride-Ethanol amine System is higher than one of lithium bromide system. And COP were obtained at various generator temperature. Finally, COP of water-lithium bromide-lithium nitrate-lithium chloride-Ethanol amine System is higher than one of LiBr system at Te=5℃, Ta=Tc=45℃ and Te=7℃, Ta=Tc=45.