Electrorheological(ER) fluid is one kind of intelligent materials with great application potential.In this paper,recent advances in material aspects of ER fluids are reviewed.Properties and problems of different ER systems such as simple dispersed phase ER fluids,composite dispersed phase ER fluids and liquid crystalline polymer ER fluids,are analyzed.To give recent development in ER materials and to promote development of the new ER materials,more emphases are given on liquid crystalline polymer ER fluids and composite dispersed phase systems,which have received extensive interests in recent years.