On the example of a single region – Sverdlovsk region – we study the evolution of the party system. The author distinguishes two stages in the development of the party system of the Middle Urals: during the existence of a multiparty system and a dominant party. Much attention is paid to the reasons of the development of the party system of the Sverdlovsk region. The author distinguishes causes such as the presence of intra-elite conflict, change the electoral law, the use of administrative resource.