Abstract: The structure and principle of shear-valve mode Magnetorheological fluid(MRF)damper are introduced in this paper. According to the flat-panel model, the damping force calculation formula of MRF damper is obtained. The dynamical characteristics of MRF damper such as damping force, displacement, velocity, frequency and electric current are studied experimentally. Results show that damping force of shear-valve MRF damper increases non-linearly with the increase of control electric current. And the adjustable coefficient k can be modified continually against the current. Under the same amplitude, coefficient k decreases with the increase of vibrating frequency, and the damping force increases with the frequency. The present work lays down a foundation for its application in the semi-active vibration control of vehicle suspension systems.