The Southern coast of Crimea (SCC) forms a separate physical and geographical area located in the extreme South of the Crimean Peninsula, between the Main range of the Crimean Mountains and the Black Sea coast. Currently, the coast of the SCC is mostly concreted (65%). Therefore, fragments of the coastal zone with preserved natural vegetation have a special environmental value, one of such sites is the Kuchuk-Lambatsky stone chaos. Kuchuk-Lambatsky stone chaos is a Specially Protected Natural Area (SPNA), but the coastal-marine area does not have any protected status. In the coastal zone of the sea, it is very important that protected areas include both land areas and coastal–marine areas. Information about the species composition and the structure of phytobenthos of the supra – and pseudolittoral zones in the marine area of the Kuchuk-Lambatsky stone chaos is presented. In total 43 species of phytobenthos have been identified: Rhodophyta – 10 species, Chlorophyta – 7, Ochrophyta – 3, Cyanobacteria – 23. Altogether 23 species were found in the supralitoral zone. During the observation period, the vegetation cover of the supralittoral zone was formed exclusively by Cyanobacteria, represented by one class, 5 orders, 10 families and 15 genera. The community, dominated by Calothrix scopulorum, Gloeocapsopsis crepidinum and Aphanocapsa incerta was found. The community is mainly formed by typical benthic, marine, and cosmopolitan species. In total 20 species of macrophyte algae were observed in the pseudolittoral zone. The Rhodophyta division is represented by one class, 5 orders, 6 families, and 8 genera. The Ochrophyta division has one class, 2 orders, 3 families, and 3 genera. The division Chlorophyta is represented by one class, 2 orders, 3 families, and 4 genera. In the pseudolittoral zone the community dominated by Ulva kylinii and U. intestinalis has been registered. It is formed mainly by annual, marine and brackish-marine, mesosaprobic species.