Low molecular weight linear chlorine terminated siloxanes (yields;71.2∼86.5%) were prepared by reactions of cyclotri-, cyclotetra- and cyclopentasiloxane with dimethyldichlorosilane in the presence of pyridine N-oxide catalyst. The amine terminated siloxane oligomers were obtained in good yields(76.2∼85.3% ) by the reaction of linear chlorine terminated siloxanes with dimethylamine at 0℃. In this investigation, we have studied on the syntheses and properties of copolymers (yields;58.0∼71.0%) obtained from the reaction of amine terminated siloxane oligomers with 1,4-bis(dimethylhydroxysilyl)benzene. The structures and properties of the copolymers were examined by FT-IR, ¹H-NMR, TGA and DSC. Initial degradation temperatures(T_Dⁱ) of the polymer I and IV were confirmed as 476 and 485℃, respectively. The thermal stabilities of the polymers were found to be increased with increasing n of (R₂SiO)_n. The glass transition temperatures(Tg) of the polymers were increased with decreasing n of (R₂SiO)_n, and the lowest Tg revealed -76℃ when n=5.