Solvent extraction reaction of Zn(II) by Alamine336 from strong HCl solution up to 10 M was identified by analyzing the data reported in the literature. The equilibrium constant of this reaction was estimated by considering the complex formation between zinc and chloride ion. The necessary thermodynamic parameters, such as equilibrium constant for the formation of complexes and the interaction parameters, were evaluated from the thermodynamic data reported in the literature. The following solvent extraction reaction and the equilibrium constant was obtained by considering the activity coefficients of solutes present in the aqueous phase with Bromley equation. $Zn^{2+};2Cl^{-};+;R_3NHCl_{org};=;ZnCl_3R_3NH_{org},;K_{ex};=;6.33;{ imes};10^2$ There was a good agreement between measured and calculated distribution coefficients of Zn(II).