This study presents information on the role of UN in the Kosovar independence process from Serbia. The study begins with data presentation on the profile of the conflicting countries namely Kosovo and Serbia, followed by a chronology of the conflict, up to the United Nations efforts made during 1999 to 2008 as an international organization in dealing with conflicts that occur between the two countries. Data and information obtained later are associated with the existing theories and concepts in International Relations from the perspective of liberalism, such as the concept of international organizations, national sovereignty, self-determination, and mediation. The conflict between Kosovo and Serbia is a complicated problem due to colliding principles applied, namely self-determination held by Kosovo and sovereignty held by Serbian. The principle of self-determination is listed on the United Nations Charter, Article 1 paragraph 2, affirming respect for the principle of equal rights and self-determination for every nation. The application of this principle collides with the principle of sovereignty which belongs to every nation, because it can threaten the sovereignty of a state. From 1990 to 2000 inter-ethnic conflicts in the territory of Kosovo, Serb massacres resulted in chaos against certain ethnic groups in the region. The conflict finally received international attention, particularly from the United Nations. The UN then sent UNMIK to handle the conflict. Based on the Resolution 1244 in 1999, the conflict in Kosovo ended with Kosovo declared as a UN protectorate and since then the peace-building process between Kosovo and Serbia is handled by the UN. After going through a long journey, on February 17, 2008 Kosovo finally declared independence from Serbia.