Silicon-containing polyimides were synthesized by solution polycondensation of bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride with 3,4-oxydianiline and 4,4'-oxydianiline, respectively. All the poly(amic acid) films could be obtained by solution-casting from NN-dimethylacetan-Lide solutions and thermally converted into transparent and tough polyimide films. The physical properties of thin films of those polyimides were compared by DSC, TGA, UV-visible spectroscopy, and dynamic mechanical analysis. The polyimide from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 3,4-oxydianiline exhibited superior energy-damping characteristic, mechanical properties, and optical transparency, whereas that from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 4,4'-oxydianiline possessed higher glass-transition temperature and thermal stability. Because of the unsymmetric structure of the polyimide from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 3,4-oxydianiline, its increasing rate of linear coefficient of thermal expansion with temperature was quicker than that of the polyimide from bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride and 4,4'-oxydial-tiline. (C) 2004 Wiley Periodicals, Inc.