The solubilities of amino acids (glycine, beta-alanine gamma-amino butyric acid, DL-alanine, DL-amino butyric acid, and DL-valine) have been measured in water and aqueous solutions of 0.5, 1.0, and 1.5 M sodium sulfate at (288.15, 298.15, and 308.15) K. Related transfer parameters are also calculated. A model, with a maximum standard deviation of 1 g per 100 g of solvent, based on the experimental data, is given to predict solubilities of these amino acids under other conditions. The results have been interpreted in terms of interactions of the amino acids with the solvent, and a qualitative comparison has been done with other cosolvents.