To realize simplified vibration reduction system, Electro- Rheological Fluid will be used. Since there was no suitable ERF for this study, material specification was created. According to this specification, particle-type ERF was manufactured and tested. To evaluate damping characteristics of laminate with ERF, three kinds of specimens were manufactured and tested. Specimen A, 20mm x 200mm, and B, 20mm x 400 mm, were used to evaluate ERF and acquire basic damping data to establish analytical model. Element specimens, 40mm x 500mm, were tested as small part of the actual structure to evaluate performance of the smart structure concept. From technical point of view, this smart structure concept has the ability to reduce vibration well but there are some technical issues to be resolved for applying to actual structures. The specification for applicable ERF and manufacturing method for smart structures are discussed.