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Simple molecular models are proposed to explain the sharp decrease of the apparent activation energy Uafor the arelaxation process, observed in amorphous polymers in the high-temperature region (50–100°C. above Tg). The intermolecular interaction in amorphous polymer is divided into collective and localized parts. The collective part is characterized by a large temperature coefficient. The aprocess includes the transition over the local potential barriers, which determines the rate of the ßprocess. The sharp decrease of Uaoccurs when the collective part of the interaction is weak; i.e., when the local potential barrier determines the net rate of the relaxation process. One of the models also explains the decrease in the magnitude of aabsorption with increasing temperature observed in some polymers. The theory predicts a marked variation in dielectric relaxation properties as a consequence of kinetic factors alone, in the absence of any structural (phase) transitions.