Abstract: The variation of viscosity of electrorheologicalsuspensions (ERSs) with shear rates is investigated underdifferent temperatures and without electrical fields bymicrostructural and rheological experiment. The results show that the valuesof viscosity under zero electrical field agree well withKrieger-Dougherty model and the values of percolation threshold dependmainly on the characteristics of particles and decrease with workingtemperatures. The variations are different in three stagesof linear startup, non-linear power law mode and Bingham mode flowing whenelectrorhrological suspensions are exposed to an electrical field.