Peculiar enantioselectivehydrolysis of N-acyl amino acid esters was found in the bilayer vesicular systems containing the tripeptide-type histidine derivative, Z-L-Leu-L-His-L-Leu. The enantioselectivity for the hydrolysis of long chain N-acyl phenylalanine p-nitrophenyl ester, C16-Phe-PNP, appeared in the binding process and was governed by an entropy factor.