From the viewpoint of the natural law, the Kosovar Albanians should have the right of self-determination. But Kosovo, a region with the strongest will for independence, the longest time of struggle, and the greatest differences with Serbia in both race and culture, still cannot achieve its independence until now when compared with Slovenia, Croatia, Bosnia-Herzegovina, and Macedonia, which were separated from the Yugoslav Federation and all became independent successively at the early 1990's. This article argues that the Kosovar Albanians were deprived of the right of self-determination by four obstacles: the historical status, the legal status of Kosovar, the insufficiency of the Kosovar Albanians' power, and the lack of support of the international community. With regard to the attitude of the international community, the author contends that, instead of ”the maintenance of regional balance of power,” ”the maintenance of regional peace and stability” is the principal reason of western countries not supporting the independence of Kosovo.