A novel polyaryloxydiphenylsilane was synthesized successfully by solution polycondensation of 2,2'-dimethyl-biphenyl-4,4'-diol with diphenyldichlorosilane and the catalyst triethylamine in toluene at 80 degrees C. Polymers with a relatively high inherent viscosity and yield were obtained when the reactions were carried out in aromatic and lipophilic solvents. The novel polyaryloxydiphenylsilane was soluble in chlorinated aliphatic hydrocarbons such as methylene chloride and chloroform as well as in polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide and also in some common organic solvents such as benzene and toluene. However, it was insoluble in both aliphatic hydrocarbons as well as in alcoholic solvents. The polyaryloxydiphenylsilane began losing weight around 400 degrees C under a nitrogen atmosphere, and the 10% weight-loss temperature was 473 degrees C. The glass-transition temperature of the polyaryloxydiphenylsilane was 102 degrees C. The glass transition could be lowered by the copolymerization technique with 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane as an aromatic diol comonomer.