The stability constants (K), standard free energies (DeltaG degrees), enthalpies (DeltaH degrees), and entropy changes (T DeltaS degrees) for the complexation of gamma -cyclodextrin with N-carbobenzyloxy (CBZ)-D/L-phenylalanine, CBZ-D/L-tyrosine, CBZ-D/L-tryptophan, CBZ-D/L-histidine, CBZ-glycine, 3-phenylpropionic acid, 4-phenylbutyric acid, 5-phenylvaleric acid, and 6-phenylhexanoic acid have been determined in phosphate buffer solution (pH 6.9) at 298.15 K by titration microcalorimetry, The trends observed in the thermodynamic parameters for 1:1 and/or 2:1 host-guest complexation correlate with the systematic structural changes of the guest molecules. On the basis of the results obtained, we further discuss the possible thermodynamic implication for the entropic control of supramolecular systems.