The Common hamster (Cricetus cricetus) is the rodent with one of the largest range (6 million km 2). There were four phylogenetic lineages earlier recovered in Western Europe, Ukraine and Bryansk Province of Russia: "North", "Рannonia", E1 and E0. E1 was previously reported from SouthEastern Poland and Western Ukraine and never been found in sympatry with "Pannonia" although the closest distance between them was estimated as 20 km. The question is whether the sympatry of E1 and E0 phylogroups exists? Special survey was arranged across Moscow, Tula, Bryansk, Oryol, Kursk, Voronezh and Lipetsk provinces to get the answer. Sequence analysis of the mtDNA control region and the cyt b gene from the tissue samples was carried out in the common hamsters captured in these areas and their belonging to a certain phylogroup was determined. For the first time a case of sympatry was revealed-in the city of Mtsensk vicinity (Oryol province). Here we discovered hamsters the both lineages-E0 and E1 at the same habitat. Hypothetically E1/E0 ranges boundary runs from Ukrainian Sumy province to NorthEast by line dividing the Russian Kursk and Oryol provinces. The existence of subclades within both E1 and E0 phylogroups suggests that diversification of phylogenetic lineages of the Common hamster in Eastern Europe may result from not single but multiple climatic events during the second half of Late Pleistocene. The phylogeographic structure of the species in Eastern Europe may be more complex than it currently known.