To understand the nature of molecular aggregation between two solvents, excess properties (e.g. excess molar volume (V ), excess Gibb's free energy of activation viscous flow (∆G* E ) and viscosity deviation of binary mixtures) are therefore needed. Thus, in the current study, the refractive index (nD), viscosity (η), and density (ρ) of binary mixtures were measured for tetrahydrofurfuryl alcohol (THFA) with ethanol, 2-propanol and 2-butanol at 298.15K. Moreover and based on experimentally obtained results, the V , the refractive index deviation (∆nD), excess molar viscosity (η E ) and ∆G* E were calculated. To correct and fit the experimental V , η