Abstract. For 20 years after the collapse of the USSR the post-Soviet countries, for the most part, turned into the independent states. So, it is not surprising that each of them has its own policy, posts and defends its own interests. The strive to preserve independence, to modernize the economy and to improve the living standards of the population remains the main driving force of interaction between the former Soviet republics within the Commonwealth of Independent States. The CIS serves as the main systemic structure in the post-Soviet space that allows the member states to harmonize their positions and, with varying degrees of effectiveness, to solve common problems. CIS provides more certainty than the regional grouping of states of the CIS. While assessing the results of different integration projects at the post-Soviet space, it can be concluded that until now Belarus and Russia fail to create a viable Union State. The Eurasian Economic Community (G5) is also far from the establishment of a customs union and an unified economic space. The fate of the Customs Union of three states (Belarus, Kazakhstan and Russia) will be defined in the upcoming years in the context of the enormous challenges of creating a common market for goods, services, capital and labor.