Electrorheological fluid (ERF) is a smart functional material which can transpose from liquid-like state to solid-like state under the action of an electric field, along with this process, the physical properties of the material will be changed such as apparent viscosity, acoustic attenuation and acoustic impendence. In this paper, three kinds of electrode surface morphology are chosen to vary the acoustic parameters of ERF systems and the leaky current when the longitudinal wave propagates parallel to the electric field. Through the analysis of the transformation laws, an optimum ERF application system for actual requirements could be easily found.