The global community is striving nowadays to find ways to stabilize social processes, as well as to solve the problem of involving socially vulnerable groups in the social and economic life and work out a strategy for reducing long-term unemployment. The development of the social economy has been chosen as the mainstream of the European Union development. A great deal of attention of European Commission is paid to studying and development of recommendations on the introduction of principles of social economy, both in the basic EU countries and in the countries that are becoming the new members of the EU. However the national approach to the legalization and support of social companies is used in each country. So, for example, in Slovakia it is supposed to create social enterprises for inclusion of disadvantaged people to the labour market first of all. Along with support of the traditional actors of the social economy, the EU is also actively developing new forms of social economy actors, social enterprises are primarily among which. The development of the principles of social economy and the activation of social enterprises is relevant for many post-Soviet countries, including Russia. However, so far in Eastern European scientific practice, many researchers do not see the difference between the concepts of social economy, social market economy, solidarity economy. The key characteristics of the social economy are considered in the article, the interrelation of social, social market and solidarity economies is observed, modern trends in the construction of the social economy of the EU are highlighted.