This paper deals with investigating molecular interaction of Polyvinyle pyrolidone polymer having molecular weight 40,000 (PVP-40) withwater and Dimethyl Sulfoxide (DMSO).Ultrasonic velocity (u), density (ρ) and coefficient of viscosity (η) were measured for solutions of PVP-water and PVP-DMSO system for different con-centrations with range 0-50 Wt%. Ultrasonic velocity measurements were done by pulse-echo technique at frequen-cy 5 MHz. The measurements were made at atmospheric pressure and room temperature. The experimental results have been used to calculate various acoustical parameters such as adiabatic compressibility (β), acoustical imped-ance (Z) free length (Lf) and relaxation time (τ), absorption coefficient (α/f2). The variations of these parameters under different conditions of concentrationhave been used to discuss the nature and extent of intermolecular inter-actions between the component molecules. The effect of polymer on solvent has also been studied.