Statistical Energy Analysis is extensively used framework for predicting the transmission of vibration and sound through complex structures. The prediction of noise and vibration levels in such structures depends on precise estimation of three parameters viz. modal densities, the damping loss factors and the coupling loss factors between the subsystems. Damping is usually characterized by the amount of energy dissipated and the most common measure of this dissipation is damping loss factor. This paper describes the effect of materials used for plate on damping loss factor. The experimental results of conventional and composite plates are compared.  Damping loss factor has been determined by Half-power bandwidth method for the plates.