Following the end of the cold war, Southeast Europe became the most unstable region in Europe, with the specter of "Balkanization" wandering once again in Europe. After the Kosovo war, the European Union's Southeast Europe strategy has become ever clearer. The program of Balkan Europeanization has been kicked off. Europe has made Balkan Europeanization a component of its long-term strategy. On the basis of analyzing the special features of the relations between the EU and the Southeast European countries, the article makes a probe into the context and contents of the EU strategy on Southeast Europe. It points out that a huge institutional gap exists between Southeast Europe and the EU and that institutional convergence seems to be the only outlet to bridge the gap. But to realize institutional convergence, it is imperative to borrow the strength of Europeanization. It was after the EU put forward the process of stability and contact that the Balkan countries saw a ray of hope for Europeanization in the dark tunnel. The articlefinally probes into the Europeanized mechanisms from the angles of the EU and Southeast Europe.