Vibrating screens are subject to high levels of acceleration and often impart significant dynamic loads on plant buildings, especially in cases where more than one of these screens are employed in process applications. To avoid premature failure and reduce plant building construction costs in critical cases, a variety of techniques are applied in practice. Most of these require substantially increased system mass, which is undesirable because of cost and static loading. With this work the Magnetorheological (MR) fluids damper was used to alter the parameter of vibrating screen and improve the screening efficiency. The displacement signals of the vibrating screen with MR fluid damper were analyzed by using bispectrum (frequency domain) and time domain methods. It is demonstrated that damping and screening efficiency could be improved by using a MR Fluid damper for changing structural damping ratio. The results show that the vibrating screen has a better quality with improved screening efficiency and decreased vibration of the base frame.