In this study some of the physical properties of polyvinyl alcohol dissolves in distilled water with different concentration (0.143%, 0.286%, 0.429%, 0.572%, and 0.715%) before and after mixing the appropriate amount of FeCl3 with aqueous PVA solutions, the Rheological properties such as shear viscosity, relative viscosity specific viscosity and reduced viscosity are measured, after that the ultrasonic velocity had been measured at frequency (40KHz). Other mechanical properties had been calculated such as absorption coefficient of ultrasonic waves, relaxation time, relaxation amplitude, specific acoustic impedance, bulk modules and compressibility. The results show that all these properties are affected with variation in density and viscosity because of the intermolecular interactions and network formation between the two types of molecules and the changes in wave pressure causes molecules to flow into vacancies in the lattice during compression phase and to return to their original positions in the lattice during rarefaction.