Viscosity measurement of coumarin derivatives were carried out in different percentage of binary solvent mixture. The study was implemented for several variation in concentration of solute as well as variation in temperature. The value of coefficient A and β was calculated from Jones Dole equation. The viscometric and thermodynamic parameters enthalpy, entropy and Gibbs’ free energy were also evaluated. The data obtained have been used to compute molecular interactions either solute-solute or solute-solvent and structure making/breaking ability of component in binary solvent mixture.