A series of samples of alumina-siloxane gel wrapped by poly(methyl methacrylate)and doped with rare earths such as lanthanum,praseodymium,yttrium,gadolinium and europium were prepared.The structure features were characterized by micrograph,X-ray fluorescence spectrum,X-ray diffraction spectrum,Fourier transform infrared spectrum and differential thermal analysis.Tests indicate that rare earths modify the electrorheological effects of the stable suspensions composed of samples stirred with silicon oil.