In this paper, the chemical structure of pectin has been modified by reacting of carboxyl group in pectin with tetrabutyl ammonium hydroxide [TBA-OH], (acid-base) reaction, to change hydrophilic properties by adding hydrophobic alkyl chains to the polymer chain in pectin, Some physical properties of both: pectin and tetrabutyl ammonium pectin; has been determined by measuring the Kinematic viscosity, degree of turbidity and density of their water solutions at different concentration.