Testate amoebae (rhizopods) from Russian tundra landscapes of the arctic mainland and islands were studied. In a total of 274 samples analyzed, 215 species and subspecies were found. More than half of the species diversity was represented by hygro- and hydrophilic, and sphagnophilic species of four genera: Difflugia, Centropyxis, Arcella and Euglypha. Almost all species belong to the cosmopolitan group of testate amoebae. Only Centropyxis gasparella, C. gasparella v. corniculata, C. pontigulasiformis, Difflugiella vanhoornei and Difflugia ovalisima might be attributed to arctic endemics because they have not been reported so far from other regions than the Arctic.