This final thesis is based on the fact that for creating the European union, as we know it today, and for connecting such a large number of states, is was necessary to elaborate in detail the structure of all institutions of the European union, and the structure and work of the European parliament is of particular importance. After the World war II , Europe was in a position of poor connectivity at all levels, especially the economy and industry and it was necessary to find a solution to this situation. The recovery of European countries was possible only by association, primarily trough production and sales, and this was followed up by other economic segments that war the key for further development of the European countries. to understand better the role of the European parliament, for starters it was necessary to elaborate the European union as an institution as well as its development. After the above, it was necessary to define the institutions of the European union and their influence on the growth and development of Europe , and as the main part of this work is the European parliament that has a very broad spectrum and has many segments, and it is impossible to omit a certain factor. After we process in detail all the segments of the European parliament we will mention its connectivity with the Republic of Croatia and try, trough all that was stated , to see how the members of the European union anticipated it should all function in the near future. The work is based on the research of the particularity and advantage of being a member of the European union, but also on the research of the European parliament it self.