After the outbreak of crisis in 2014, the situation in Ukraine became a hot issue in the world, and its diplomatic policy has aroused the attention of scholars. After independence, Ukraine used balanced diplomacy as the main diplomatic approach to deal with the relations with Russia and the European Union (EU). In the end of 2013, although the diplomatic goal was joining in the European integration, Ukraine suspended the preparation of signing Association Agreement with EU. Moreover, Ukraine announced to strengthen economic relations with Russia and the Commonwealth of Independent States. This decision of Ukraine caused discontent from pro-Western people. After that, domestic crisis in Ukraine was broken out. This made Viktor Yanukovch and his government out of office. Along with the appearance of pro-Russian armed forces in several eastern regions, the constant outbreaks of armed conflicts escalated the tense situation of Ukraine. This crisis which caused by the different national identities of Ukrainian citizens showed the importance of balanced diplomatic policy and the difficulties of policy implementation. As a country which was wandering between Russia and the EU, the balanced foreign policy was still a suitable diplomatic policy for the actual conditions of Ukraine, even though its implementing effect was not ideal. This thesis focused on the balanced diplomacy of Ukraine between Russia and the EU. It would discuss the main cause which affects the diplomatic policy of Ukraine. And this main cause could explain why Ukraine must take balanced foreign policy to deal with the relations with Russia and the BU. With the complex interdependence theory and the balanced of power theory as basis, it considered that interdependence was the main cause for the maintenance of diplomatic relations among Ukraine, Russia and the EU. However, as a country with large dependence, the asymmetry of interdependence led Ukraine into a passive position in foreign affairs. In some specific fields or issues, Russia and the EU used the dependences of Ukraine as a power resource to affect Ukrainian foreign policy. Therefore, they could make Ukrainian foreign policy benefit them. For protecting national interests and independence, Ukraine must carry out the balancing acts between Russia and the EU. In order to strive for more favorable position in the diplomatic relations, Ukraine adjusted foreign policy directions constantly according to its internal and external conditions. The cases of Black Sea Fleet, Crimea, the European Neighborhood Policy and the Free Trade Area would be analyzed for supporting and proving these hypotheses. Key Words: Ukraine; Russia; the EU; relations; interdependences; balanced acts