The description of polymer relaxation properties makes it possible to characterize the influence of polymer structure on its useful properties, i.e., stability and resistance. To determine the profile of the relaxation properties of the linear, hyperbranched and dendrite unsaturated polyester resins, the synthesis of the oligoester as the model compounds was performed. The structures of the obtained model compound were confirmed by elemental analysis and 1H NMR and FTIR spectroscopy. The determination of the α relaxation processes for model oligoester allowed us to describe the practical properties of commercial compounds. The description of the relaxation process may facilitate the interpretation of the dependence between useful properties of polyesters and their molecular structure. The results of the experiments allowed us to improve the technology of the synthesis processes and to extend the range of their usage.