Recently,　electrorheological　fluids　(ERFs)　have　emerged　as　a　potential　technology　for　implementing　semi-active　control　in　smart　structure　and　vehicle　applications　to　efficiently　suppress　vibration.　The　rheological　behavior　of　ERFs　under　an　electric　field　is　important　in　engineering　application.　The　work　described　here　involves　experimental　research　into　the　rheological　behavior,　under　a　variety　of　electric　fields,　of　three　kinds　of　ERF:　(C6H　10O5)n,　TiO2-CeCl3,　and　SrTiO3/PANI　(PANI　Combining　double　low　line　polyaniline).　We　aim　to　design　a　high-performance　ERF　and　display　an　ER　effect.　Results　show　that　different　kinds　of　ERF　have　different　yield　properties,　especially　under　the　conditions　of　both　post-yield　and　higher　shear　rates.　In　terms　of　the　trend　in　behavior　of　the　ER　effect　shown　in　the　experimental　curves,　the　expression　for　the　relation　between　dynamic　shear　stress　and　static　yield　stress　has　also　been　investigated.　Both　the　highest　negative　and　the　highest　positive　differential　values　have　been　obtained.　We　also　show　that　apparent　viscosity　shows　three　different　trends　in　behavior,　based　on　at-line　start,　non-linear　power-law　and　Bingham　power-law　(Sisco)　flow　behavior.　The　relative　variation　values　of　ERFs　at　low　and　high　shear　rates,　respectively,　are　shown.　©　2006　IOP　Publishing　Ltd.