Binodal data for the ethanol/propan-1-ol/propan-2-ol-dipotassium 2,3-dihydroxybutanedioate aqueous two-phase system (ATPS), the propan-2-ol-disodium 2,3-dihydroxybutanedioate/diannmonium 2,3-dihydroxybutanedioate ATPS, and the ethanol-potassium sodium 2,3-dihydroxybutanedioate ATPS were determined at 298.15 K. An empirical equation was used to correlate binodal data, and it showed satisfactory accuracy in binodal data fitting for all of the determined systems. The phase-separation abilities of the investigated salts and the water-miscible alcohols were compared by the plotting of binodal curves in mass fraction. The phase-separation abilities of the investigated alcohols are in the order propan-1-ol > propan-2-ol > ethanol, and those of salts are in the order disodium 2,3-dihydroxybutanedioate > potassium,sodium 2,3-dihydroxybutanedioate > dipotassium 2,3-dihydroxybutanedioate > diammonium 2,3-dihydroxybutanedioate. However, the two-phase area of the investigated alcohol-dipotassium 2,3-dihydroxybutanedioate ATPS is higher than that of the alcohol-disodium 2,3-dihydroxybutanedioate/potassium sodium 2,3-dihydroxybutanedioate/diammonium 2,3-dihydroxybutanedioate ATPS. The salting-out abilities of the common cations (K(+), Na(+), and NH(4)(+)) were discussed by comparing their effective excluded volume (EEV) in the propan-2-ol-water component solvent and the binodal curves plotted in molality. They are in the order Na(+) approximate to K(+) > NH(4)(+).