Abstract: The author describes the lot of extinct and endangered mammal species inhabitants of various continents. Over the last 2,000 years, on the territory now occupied by the USSR, 11 species and sub-species of mammals died away and several dozens of species and sub-species are now endangered or rare and require special conservation measures. Big Felidae species include tiger (150 170 animals), leopard (38-48 animals, of which 20-25 permanently live in the Far East, the rest migrating), snow leopard, whose population reduced drastically (about 1,000 animals), caracal, Central Asia lynx, and manul.