Here, we describe the analysis of kinetic and thermodynamic parameters for binding of peptide and nonpeptide dimerization inhibitors to immobilized HIV protease (HIVp) monomers by using surface plasmon resonance. Molecular interactions were investigated at different inhibitors concentrations (0-80 μM) and temperatures (15-35°C). The kinetic, equilibrium and thermodynamic parameters have been determined. It was found that both inhibitors were characterized by similar interaction parameters. The complex formation is entropically driven process for both inhibitors. The entropic term(-ТΔS) had the value about -20 kcal/mol while the enthalpic term (ΔH) had the positive value about 14 kcal/mol and counteracted the complex formation.