A novel water-soluble cross-linked polymer catalyst containing L-histidine and quarternary trimethylammonium groups, which was imprinted by a racemic transition-state analogue of phenyl 1-benzyloxycarbonyl-3-methylpentylphosphonate for the hydrolysis of p-nitrophenyl N-(benzyloxycarbonyl)-L (or D)-leucinate (Z-L (or D)-Leu-PNP), exhibited the notable substrate stereospecificity for Z-L-Leu-PNP in the hydrolyses of enantiomeric amino acid p-nitrophenyl esters in 10 vol% DMSO (or MeCN)-Tris buffer pH 7.15) at 303 K. Copyright (C) 1996 Elsevier Science Ltd.