The modern concept of biodiversity is all-embracing; in ecological and geographic aspects it should be viewed as different structural and functional levels of the organization of life (Biodiversity, 1988; Yurtsev, 1992). The basic level of biodiversity is the species. Lower ranks, such as population-race, genotype, genetic etc., are also, however, of great importance in assessing taxonomic diversity. They are encountered at the level of primary units represented by natural spontaneously differentiated populations which are a basis for evolution. In contrast to species level diversity, they are not well investigated, particularly in field recording. A review of the research of known population-ecology and population-genetics schools in Ukraine (Donetsk, Kiyv, Lviv, Uzhgorod, Kharkiv etc.) suggests that basic information on population-genetic diversity of plants is at an early stage of development in this country. Most works deal with species separated using a typologic-taxonomical approach within narrow monotypic standards and ignoring (or with restricted use of) the population-genetic approach (cytologic, phenetic, biochemical etc.). Recent research in that aspect has concentrated only on certain taxa (including Arnica, Pinus, Ornithogallum, Trollius, Narcissus and Veronica) in limited areas. A critical taxonomic revision of the Ukrainian flora based on the new methodology of a population-ecological approach using advanced taxonomic methods is therefore important. The result of that research might be the creation of a database of floristic biodiversity at a populaton-race level. Such a database would have to contain information not only on formal floristic taxonomy but also about features of real differentiation of natural populations (caryotypes, caryological maps, maps of phenetic distributon and occurence, phenotypic differentiation, ecotypes etc.). At present, however, realization of this database is problematic. Finally, regional protection of landscapes and ecological diversity as a source of genetic differentiation of populations seems to be the most efficient type of conservation of this diversity. For aspects of biodiversity discussed here, conservation ex situ may be more appropriate, and could be more efficient than for taxa at species rank.