A steppe biome of Ukraine occupies about 30 million hectares. Specially protected forbidden steppe areas are about 45 thousand hectares, 11,054 hectares of which are concentrated in the oldest on the planet steppe reserve “Askania-Nova”, with the status of “Biosphere Reserve” since 1985. Long-term studies of reserved succession in the steppe reserves of Ukraine enable to assess the results of an influence of the protected regime on conservation of the specific animal diversity in different types of nature using. On the present territory of the Biosphere Reserve “Askania Nova” the protected regime is introduced since 1898. Numerous studies show that a mechanism of reserved succession in the steppes comes after the stopping of grazing pressure, and as is known to be accompanied by accumulation of the steppe litter, mesophytisation processes, composition change and increasing of grass height, that distinctly negative impacts on the population status of the steppe species making up the trophic chains. The consistent expansion of the protected area and strengthening of the regime from the beginning of 70-ies of XX century at the virgin lands of the Biosphere Reserve “Askania Nova” entailed reduction of little souslik population (Spermophilus pygmaeus Pallas, 1778), which from the large species became extremely rare. The species became extinct completely at the other protected areas or its state is critical. At the same time it is observed the disappearance of other steppe species of rodents: great jerboa (Allactaga major Kerr, 1792), hamster (Cricetus sricetus Linnaeus, 1758), sagebrush vole (Lagurus lagurus Pallas, 1773). Disappearance of the souslik catastrophically affected species such as a steppe eagle (Aquila rapax Temminck, 1828), its last reliable nest in the nature of Ukraine was dated to 1981; and a steppe polecat (Mustela eversmanni Lesson, 1827), traces of which are recorded less and less. A corsac fox (Vulpes corsac Linnaeus, 1758) remained only in the eastern protected steppes (Red Book of Ukraine, 2009). High grass of the protected steppes influences negatively on the nesting and staying of a number steppe species of birds. In Askania-Nova some species stopped the nesting such as demoiselle crane (Anthropoides virgo Linnaeus, 1758) and BlackWinged Pratincole (Glareola nordmanni Nordmann, 1842). Their nesting was recorded at the beginning of XX century. However, the protected areas are refuges for many rare species of birds. So, in years with low grass stand the protected steppes become the main place of wintering East54 ern European population of the Great Bustard (Otis tarda Linnaeus, 1758). Over the past 10 years, the winter numbers of this species in the Biosphere Reserve “Askania Nova” reached 1100 individuals because of low herbage, and rarely exceeded 200 with high herbage. In the case of the presence of grazing pressure on the reserve steppe, that is practiced in one of the plots in the Biosphere Reserve “Askania -New” in the area of 2370 hectares, the conditions are created for the long-term staying of a number of migratory and wintering rare bird species: Red-breasted Goose (Rufibrenta ruficollis Pallas, 1769) from a few dozen to 12 thousand individuals, Lesser White-fronted Goose (Anser erythropus Linnaeus, 1758) - a few tens of individuals annually, Common Crane (Grus grus Linnaeus, 1758) from 12 to 44 thousand individuals at the same time. This is connected with significant increase of annual temperature of the southern steppe region, which coincides with the planetary warming, as well as a significant watering of once steppe areas by irrigation systems. Active penetration of the forest and steppe birds’ complexes is due to the formation of the field wood plantations in the once steppe ecosystems. Typically, flocks of migratory birds are accompanied by large birds of prey: Golden Eagle (Aquila chrysaetos Linnaeus, 1758), White-tailed Eagle (Haliaeetus albicilla Linnaeus, 1758), Imperial Eagle (Aquila heliaca Savigny, 1809). Moreover, their number has consistently increased the last few years. The high herbage and periodic outbursts of public voles’ population (Microtus socialis Pallas 1773) on the protected sites of North Sivash conduce to maintenance of a high population of marsh owl (Asio flammeus Pontoppidan, 1763). Significant changes are traced in the structure of entomological complex, which also loses rare steppe species. They are replaced by forest-steppe species (including some rare) and even the forest, which find here new ecological niches and settle successfully. In the process of the long-term observations for dynamics of steppe ecosystems, we can state that all the steppe protected areas of Ukraine, including the largest reserve steppe of Europe in Askania Nova, are not self-regulating ecosystems, their incompleteness is determined by the absence of a powerful consuming block of the first order in the form of large herbivores and reserve succession does not create the conditions for the preservation of the rare zonal biodiversity. The situation is complicated by insufficient settlement at the legislative level of the regulations on the necessity of pointed management of ecosystems which have lost the ability of self-maintaining autocoenoregulation and autocoenorestoration. The necessity of development and implementation of technology of the artificial breeding of rare animal species with their further reintroduction to the nature of steppes remains actual problem.