The telechelic polybutadiene is a random terpolymer of cis-1,4, trans-1.4. and 1,2 vinyl isomers. The equation xiv(In by Gibbs- DiMarzio for the glass transition temperature(T_g) of a copolymer in terms of the microstucture and the T_g''s of the three homopolymers were used to verify the glass tran.iition behaviors of this prepolymer. The Tf of the polyurethane based on polybutafiene was measured with dilatometry and differential scanning calorimetry. The T_g of the liquid prepolymer is 191°K by DSC at the heating rate of lO℃/min. and its calculated value is 185°K, respectively. The fractional free volume, fg, at the T_g is apporximately 0.025±0.003, and the differences between the expansion coefficients above and below T_g are 3.67×10^-4K^-1 and 4.44×10^-4K^-1 by dilatometry in these compounds. The "universal constants" C₁^g, C₁^g values from the Williams-Landel-Ferry equation were modified for the temperature range between T_g and T_g+100℃. The peaks of the tanδ were also shifted at different frequencies in dynamic tests, and the activation energy (ΔH) for the process was obtained from the log a_T against the reciprocal of the absolute temperature.