This paper deals with the enantioseparation of phenylsuccinic acid (H(2)A) enantiomers by liquid-liquid reactive extraction using beta-CD derivatives as aqueous selectors. Cyclodextrin and its derivatives can interact with guest molecules selectively to form complexes with different stabilities. Cyclodextrin derivatives are not soluble in organic liquids, but highly soluble in water. In this work, hydroxypropyl-beta-cyclodextrin (HP-beta-CD), hydroxyethyl-beta-cyclodextrin (HE-beta-CD) and methyl-beta-cyclodextrin (Me-beta-CD) were selected as chiral selectors in aqueous phase for the reactive extraction of phenylsuccinic acid enantiomers from organic phase to aqueous phase. The results show that the efficiency of the extraction depends, often strongly, on a number of process variables, including the types of organic solvents and beta-CD derivatives, the concentrations of the extractants and H(2)A enantiomers, pH and temperature. HP-beta-CD, HE-beta-CD and Me-beta-CD have stronger recognition abilities for R-phenylsuccinic acid than for S-phenylsuccinic acid. Among the three kinds of beta-CD derivatives, HP-beta-CD has the strongest separation ability. Excellent enantioseparation was achieved under the optimal conditions of pH of 2.5 and temperature of 5 degrees C with a maximum enantioselectivity (a) of 2.38. Reactive extraction of enantiomers with hydrophilic beta-CD derivatives is of strong chiral separation ability and can be hopeful for separations of various enantiomers at a large-scale.