This thesis is a normative study of immigrant policy. The main question asked is how liberal democracies should respond in terms of immigrant policy to the fact that they now constitute multicultural societies. Divergent answers to this question are provided by two different schools of thought in the liberal tradition of political philosophy - liberal nationalism and liberal multiculturalism. The arguments presented by some prominent proponents of these two political philosophies are investigated and a favourable stance is taken towards liberal multiculturalism and its policy of immigrant integration as opposed to a liberal nationalist policy of immigrant assimilation. A question of great importance for liberal multiculturalists is whether the social stability and unity provided by national identity can be replaced in the multicultural society by new forms of postnational identities and communities. Some thoughts regarding this issue are presented and it is concluded that the development of such postnational identities and communities is likely since they already exist in some multinational states. The next object of investigation is the current Swedish immigrant policy expressed in a 1997 government bill. It is concluded that the current Swedish immigrant policy accords well with the policy of immigrant integration favoured by liberal multiculturalists.