Abstract: Electro-Rheological (ER) fluid is a kind of new smart material which is very useful to industrial applications as its mechanical properties canbe changed very quickly and also reversely by applied electric field.In this paper, the research advances in the materials and the characteristics of ER fluid are reviewed at first, the applications of ER fluid to the vibration control of rotating machineries and to the engine mount and suspensionsystem of vehicles are reviewed in detail. The applications of ER fluid...