The paper is devoted to investigation of physico-chemical properties of the C₇₀-L-lysine derivative aqueous solutions. Within the framework of our investigation, we have studied the concentration dependences of density, average molar volume and partial molar volumes of the solution components, specific and molar conductivities, dissociation constant, apparent degree of dissociation, ζ – potential as well as concentration dependences of the C₇₀-L-lysine associates size distribution in aqueous solutions. Additionally we have used the semi-empirical VD-AS (Virial Decomposition Asymmetric Model) model and calculated the excess thermodynamic functions of solutions and solution components.