Osmotic coefficients are inferred from vapor pressure osmometry measurements that were performed at T = 298.15 K for ternary amino acidelectrolytewater systems with variation in the concentrations of amino acid (aminoethanoic acid, glycine) and electrolyte (NaCl) up to high concentrations of aminoethanoic (3 mol.kg(-1)) and NaCl (3 mol.kg(-1)). From the consideration of the GibbsDuhem equation at mutual data treatment, interparticle interactions in ternary aminoethanoic acid-NaCl-water systems have been deduced in a wide concentration range. A two-parameter fit (third order terms in the power series) according to Bower and Robinson is used for calculation of component activity coefficients.