The publication highlights the environmental features of one of the most urbanized regions of Ukraine - its capital, Kyiv. The city is described as an ecosystem of the past, present and future. The role of geographical conditions in the formation of the urbosphere in the territory of Kievan Rus is determined, the ecological state of various components of the environment of the capital of Ukraine at the turn of the third millennium is shown. Modern data on the role of the natural conditions of the Middle Dnieper in the post-glacial time, in the formation of the initial ecosystem of Ancient Kyiv, information on geological conditions, relief and man-made disasters, landscapes and climate, surface waters and their ecological state, economic, geographical and demographic problems of the City, post-Chernobyl problems, medical and geographical situation, recreational resources, outlined the prospect of the development of Kyiv as a significant element of the urbosphere of Ukraine.