The macroscopic properties of a polymer composite are significantly affected by the properties of the inclusions, size, shape, and distribution. Finite element (FE) modeling provides a viable approach for investigating the effects of the inclusions on the macroscopic properties of the polymer composite. In this thesis, we use the finite element method to investigate ultrasonic wave propagation in polymer matrix composite with a dispersed phase of inclusions. The finite element models are made up of three phases; viz. the polymer matrix, inclusions (micro constituent), and interphase zones between the inclusions and the polymer matrix. The interphase zone is explicitly modeled to study the effect of the properties of the interphase on the polymer composite. The analysis is performed on a three dimensional finite element model and the attenuation characteristics of ultrasonic longitudinal waves in the matrix are evaluated. The analysis is performed using the finite element code ABAQUS. We investigate the attenuation in the polymer composite by changing the size, volume fraction of inclusions, and interphase material properties. The effect of interphase properties like the Young's modulus and the thickness of the interphase layer on the wave attenuation characteristics of the polymer composite are studied by conducting a sensitivity analysis. The effect of loading frequency of the wave on the attenuation characteristics are also studied by varying the frequency in the range of 1 - 4 MHz.Results of the test revealed that a higher volume fraction of inclusions gave higher attenuation in the polymer composite compared to the lower volume fraction model. Smaller size inclusions are preferred over larger sizes as they give higher wave attenuation. It was found that the attenuation characteristics of the polymer composite are better at higher frequencies compared to lower frequencies. It is also concluded that the arrangement of inclusions in a polymer composite plays a significant role in the attenuation characteristics of the composite. The Young's modulus and the thickness of the interphase layer also play a vital role in the wave attenuation characteristics