The Kurgalsky Nature Reserve is situated on the south-western coast of the Gulf of Finland near the Estonian border. It is included in the network of Helcom Baltic Sea Marine Protected Areas, and Wetlands of International Importance (Ramsar Sites). This area is a refuge for a great number of rare and threatened species and biotopes of high conservation value. Based on the research carried out by the authors in the 2000s in the Kurgalsky Reserve and analysis of all previously published information on the vegetation cover of the protected area, the most valuable biotopes were revealed. To identify the biotopes of high conservation value floristic, geobotanical, geographical and ecotopic criteria were taken into account. The biotopes were characterized on the basis of occurrence of rare plant communities, rare species of vascular plants, bryophytes and lichens, biologically valuable forests, including species and habitat types of European importance. Exceptionally valuable are relict broad-leaved and spruce-broad-leaved forests with a rich complex of typical nemoral species. Noteworthy are dune pine forests and black alder communities. A high concentration of red-listed species is also characteristic of dry grasslands, especially in the southern part of the reserve. Of particular interest is the large ombrogenic bog Kader. Many protected and threatened plant species very rare in the Leningrad Region are abundant in the Kurgalsky Reserve, and sometimes they are typical components of its plant communities.