The Ukrainian Polissia is a distinctive region in terms of biodiversity, with a significant number of northern and boreal species and communities, as well as Central European species in the Western Polissia. The research region stretches from west to east for 750 km, and from north to south for 120â150 km. In the northeast direction, its territory gradually narrows to 50â80 km and constitutes a significant part of the important ecological corridor of Eastern Europe. Background. The natural conditions of the Ukrainian Polissia are favorable for the formation of coniferous, broadleaf and mixed forests, which are zonal communities here. The widespread distribution of fluvioglacial sediments causes the predominance of sandy sod-podzolic soils and associated pine forests. The high groundwater table and the low surface area contribute to the development of eutrophic peat bogs. All this leads to the formation of a diverse vegetation cover, which contributes to the representativeness and significant preservation of floristic and coenotic diversity. One of the key roles in the protection of rare species of phytodiversity in the Polissia region of Ukraine belongs to multifunctional protected areas, including the category of âregional landscape parksâ. They cover more than 200 species of vascular plants of the Polissia region, with diffeÂrent conservation statuses â from the international level of protection to the regional one. Materials and Methods. The study was conducted using conventional field (route-based, geobotanical descriptions of key areas) and desk methods. The species names are given according to the International Plant Names Index, and their belonging to the protected categories is based on the conservation criteria and protection levels accorÂding to the regulatory documents. Results and Discussion. The materials of the research of phytodiversity of five regional landscape parks (Prypiat-Stokhid, Nadsluchanskyi, Ptashynyy Rai, Mizhrichenskyi, Yalivshchyna), in particular rare species, are presented, as evidenced by their diversity, including a number of glacial relics, endemics and borderline species located at the southern or eastern border of the distribution area. Conclusions. The study has revealed that the rare vascular plant flora of the Polissia regional landscape parks is represented by 56 species included in the Red Data Book of Ukraine, 145 species under regional protection of three oblasts of the Polissia region, nine species from Appendix I of the Bern Convention, four species from Appendix II of CITES, and three species included in the European Red List. Two RLPs are the most sozologically representative in the study area: Nadsluchansky (six species of international protection statuses, 30 species of the Red Data Book of Ukraine, 107 species of regional protection level) and Mizhrichynsky (14 species with international protection statuses, 28 species of the Red Data Book of Ukraine, 51 species of regional protection level), which is determined by the peculiarity of natural conditions, habitat diversity and area of the territories. regional landscape parks as a category of nature reserve fund of regional status within the Polissia region of Ukraine cover most of the representative habitats, which include a corresponding number of rare species of different levels of protection, namely: forest (87 species), herbaceous (85 species), marsh (36 species) and aquatic (30 species) habitats.