Both unification and harmonization of law are often mentioned as basic goals in official documents related to the promotion of economic integration of the countries — members of the Eurasian Economic Community. It is explainable by the fact that the presence of a unified law at the area of a common market should provide an essential decrease of transaction costs, which in its turn would result in stimulation of trade on the given market. The experience of the same processes of harmonization of law in EU demonstrates as the existing obstacles for it, as possible ways to overcome them.