Ukraine plays an important geo-economic role in the Eastern Europe. This country is the main transit corridor of the EU's imported Oil and Gas from Russia. On the other hand, the EU is Ukraine's major trade partner. Despite some prevailing rhetoric, the EU is not considering the membership of Ukraine. Although European Union has concerned about Russia's heavily influence over Ukraine, there is little indication that the EU intends to prevent Russia from maintaining it influence in that country. some the reasons that accounts for EU's ambivalent policy towards Ukraine and the enlargement fatigue in the EU, different positions of the EU's main powers with regard to Eastern Europe politics and EU's priority as maintaining good relations with Russia as its main energy partner.