Most eucaryotic soil algae are absent from handbooks and floras of freshwater algae. In Ukrainian soils about 800 species of algae have been recorded, but only 20% have been confirmed by subsequent collections. Soil algae are very sensitive to changes of invironments. The first to vanish from algal communities are the yellow-green, partly diatom and green algae, especially species which are rare or absent from water ecosystems. Some rare species may now only exist in culture collections. Species with local but rather abundant distributions could be preserved in the same way as water algae, through habitat preservation. The only known population of Schizogonium murale Kutz in Ukraine could, for example, have been preserved in such way, but destruction of its habitat caused this species to vanish. About 40% of the abundant species have broad habitat requirements (mostly blue-green algae, chlorellaceous and ulothrichaceous green algae, eustigmataceous species etc.). They do not need special protection mesures. The greatest number of rare species of soil algae with closely-defined habitat requirements are to be found in the Crimea mountains and the Carpathians. In the plains, the highest divesity of soil algae is in the Forest-Steppe zone.