Viscosities, eta, for glycine and L-alanine have been measured in (0.2, 0.4, 0.6, and 0.8) mol.kg(-1) aqueous dipotassium hydrogen phosphate (DKHP) solutions at temperatures T (288.15, 298.15, 308.15, and 318.15) K. The change in viscosity of amino acids with an increase in DKHP concentration and temperature is attributed to amino acid-DKHP interactions. The viscosity B-coefficients and viscosity interaction parameters obtained from the Jones-Dole equation and transition state theory, respectively, have been discussed to interpret interactions between ions of amino acids and dipotassium hydrogen phosphate.