The modern world of policy is characterized by existence of the most various political systems. In this regard, it is appropriate to remind of classification of party systems of Dzhiovanio Sartori. In this classification first of all, a multi-party system with a dominant party draws attention. This system attracted our attention due to the fact that it is characteristic to many countries. Sartori distinguishes 3 modification of a multiparty system with a dominant party. He writes about a predominant party system, a dominant party system and an authoritarian dominant system [1, p. 260-261]. It should be noted that, in Dzh. Sartori opinion, these systems significantly different from each other. However, Sartori was able to reveal similarities. A convincing illustration of this fact is the process of formation of multi-party system in the former Soviet space. This will be illustrated below later. Number of researchers believe that the «one-party system derives its strength from the struggle with imperial, conservative and traditional forms of power. In modernizing societies multiparty systems are weak» [2, p. 419]. It should be noted that, regardless the form of domination, all the dominant party systems have similarities. This is because, these party systems decide essence common challenges. One of the such feature is the spread of patronage and orientations of cash bonds. The second feature is that the dominant parties often act as a center party. This creates more opportunities for ideological maneuvering. However, the dominant parties of different systems also have differences. The most important difference is the methods of dealing with political opponents. The predominant and dominant party systems prevail legitimate democratic mechanisms, like competition of authoritarian ideologies of dominant systems, which leads to a very tough fight. The second difference is, being the ruling party, the dominant party determines the structure of the executive branch. In the dominant authoritarian systems, as a rule, parties serve to enhance the influence of a small group. The third difference is that, in predominant party and dominant systems parties are usually used for the modernization political relationships. In authoritarian systems the dominant ruling party often use non-democratic practices and procedures to maintain the dominance of the ruling group. As stated above, we have paid so much attention to the multi-party dominant party because the party system functioning in the post-Soviet space are mostly the dominant party systems of various modifications. This conclusion is strongly supported by concrete analysis of the formation of parties and party systems in some countries of the former Soviet Union.