Аннотация:The buccal armature usually plays important role in the feeding process of gastropods. By this term, the cuticular structures found in the buccal cavity, e.g., radula and jaws, are meant. In the case of nudibranchs, the features of buccal armature have a special importance in taxonomical studies due to specialization on different feeding objects and absence of other hard structures as shell and operculum. Nevertheless, data on the functional role of the buccal armature are insufficient. In the present study, we compared the general and fine morphology of the buccal armature in several species of nudibranchs with different feeding preferences. To understand the position of the buccal armature within the buccal complex, we constructed computer-based three-dimensional reconstructions for several species. To examine the morphology of the radula and the jaws we used methods of SEM and TEM. The arrangement of the radular teeth on the working plane (the odontophoral bend) was observed by SEM. The main characteristics depending on the feeding objects are the shape of the radular teeth, the shape of the denticles on the radular teeth and the masticatory processes of the jaws and the length of the cutting edge of the teeth (if present) as well. These characteristics may change during the ontogenesis, like in Dendronotus frondosus (Ascanius, 1774) or remain the same in size and shape, like in Coryphella verrucosa (M.Sars, 1829) and Eubranchus rupium (Møller, 1842). The changes in morphology of the buccal armature are the reflection of the changes in feeding preferences. This study was supported by the Russian Foundation of Basic Research, Grant No. 18-34-00251.