Polyurethane (PU) is interesting to study the electrical properties because it can be tuned by controlling hard/soft segments. In addition, structures can response to the electric field due to the dipole moment in hard segment. This research prepared polyurethane via solution polymerization using N,N-dimethylacetamine (DMAc) as a solvent and varying molar ratio of methylene diphenyl diisocyanate(MDI) and ethylene glycol, using the two different structures of polycarbonate diol(PCD), Eternacoll®UH200 and Eternacoll®PH100. FTIR result shows disappearance of the NCO stretching band at 2273 cm-1 revealed the reaction of –OH with –NCO to form PU. Peaks at 1540 cm-1, 1705 cm-1 and 3300 cm-1 were observed and attributed to NH-bending, carbonyl stretching and NH-stretching from the urethane linkage respectively. DSC results showed that miscible of hard/soft segment decreased when the molecular weight of polycarbonate diol increased. Subsequently, dielectric constant and dielectric loss were obtained from LCR meter at 10-106 Hz and revealed that the higher percent hard segment content, the higher of dielectric constant. This work can represent polyurethane based PCD, which provides its flexibility and manufactures easily for being utilized in actuator applications