The thermal analysis techniques-Differential Scanning Calorimetry and ThermoStimulated Current-have been used to characterize a polyurethane high solid coating. The glass transition temperature, as determined by DSC, is 60 degreesC. Below this glass transition temperature, an alpha (sub) dielectric relaxation mode has been observed; it corresponds to cooperative movements precursor of the glass transition. The alpha (ss) dielectric relaxation mode, located at approximate to T-g has been attributed to movements of soft sequences of the amorphous phase liberated at the glass transition temperature. The analysis of the fine structure shows that they are constituted of elementary processes characterized by relaxation times following a compensation law. Above T-g, the alpha (hs) dielectric relaxation of hard sequences has been shown. It corresponds to hard sequences hydrogen bonded in polyurethane.