During the development process, particularly Middle and Eastern European Countries have increasingly integrated into the Union economy while parliaments, governments, public and private sectors have put forth significant effort to prepare for membership to European Union. European Union, on the other hand, prepared a financial framework in 1989 to actively support such efforts. Thus the Union financial and institutional regulations were realized to finance the process of transition to market economy. In this regard, Poland has quickly completed the necessary steps for harmonization and accelerated its efforts towards this goal. Following the radical change Poland experienced after 1989, the process of democratization and transition to open market economy. In our study we compared and investigated Poland economic and political situation before joining European Union, with the developments during the harmonization process and its economic structure today. In this process, it will be appropriate to take a look at Poland recent political and economic life as well as the reasons as to why Poland is an important state for Europe.