The aim of the article is to present international economic integration as one of the mega trends that infl uence on the redefi nition of the factors of socio-economic development. The research procedure includes three stages. In the fi rst stage, the most important modern mega trends of socio-economic changes are organized in a synthetic way. In the second step, the genesis and changes of the process of international economic integration are elaborated. In the third stage, the infl uence of international economic integration on the changes of factors of socio-economic development is systematized. This study is being carried out as part of the FORSED research project (http://www.forsed.amu.edu.pl) fi nanced by the National Science Center as part of OPUS competition 10 – 2015/19/B/HS5/00012: New challenges of regional policy in shaping the socio-economic development factors of less developed regions.