Viscosities for different concentrations of crude oil solutions from 10 to 50 %(v/v) have been studied using benzene as a solvent at temperature ranging from 303 to 318 K. Four different relations: Huggins, Kraemer, Martin and Schulz-Blaschke were used to study the oil solution interaction in benzene by viscosity measurement. Viscometric constant values in terms of solute-solvent interaction. These relations were successfully applied for the study of macromolecular interaction. The validity of these relations concerning the interaction of crude oils with benzene was studied. Thermodynamic parameters for viscous flow were also evaluated such as free energy change of activation (ΔG*), enthalpy change of activation (ΔH*) and entropy change of activation (ΔS*) as a function of concentration of crude oil solutions and temperature.