Migration is one of the most remarkable phenomena of the whole human history. Demographic growth, technological changes, political conflicts and wars were always accompanied by significant populations’ movements. In XX century the meaning of migration for social life, economy and politics increased rapidly. The aim of this paper is to present a brief review of the most interesting and well-based approaches to migration process, to describe an evolution of «migration theories» from a very simple model of human capital to modern complex econometric systems. The second point is to analyze the migration policy of different countries. The theoretical sentences are completed by relevant statistical data and empirical examples that promote a better understanding.