The electrorheological (ER) suspensions containing the powders of silicone aluminum oxygen gel compilihentioned with PMMA and silicon oil were prepared. The viscosity of these suspensions and their influencing factors, such as electric field strength and particle concentration, were detected. By use of rare earth as agent to dope the samples, the experimental results show that, with the increasing of field strength and particle concentration, ER effect changes. The electrorheological (ER) suspensions containing the powders of silicone aluminum oxygen gel compilihentioned with PMMA and silicon oil were prepared. The viscosity of these suspensions and their influencing factors, such as electric field strength and particle concentration, were detected. By use of rare earth as agent to dope the samples, the experimental results show that, with the increasing of field strength and particle concentration, ER effect changes.