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Dilution enthalpies of six enantiomers of α-amino acids(L-alanine vs.D-alanine,L-serine vs.D-serine,and L-proline vs.D-serine)in pure water were determined respectively at different temperatures(T = 288.15 to 323.15 K)by isothermal titration calorimetry(ITC).Homochiral enthalpic pairwise interaction coefficients(hxx)of them at each temperature were evaluated from dilution enthalpies determined according to the McMillan-Mayer theory.The hxx values of α-alanine and α-proline enantiomers are all positive(hLL > hDD > 0),signifying enthalpically repulsive effects,while those of α-serine enantiomers are all negative(hLL < hDD <0),signifying enthalpically attractive effects.However,for both of the cases,the hxx values increase uniformly and gradually with the elevating temperatures.The results indicate that there exists a slight but significant enthalpic discrimination effect in the homochiral pairwise interactions of these α-amino acid enantiomers,and that the increase of temperature promotes the predominance of hydrophobic interactions in the solutions,characterized by the positive growth of hxx values.