Migration is a phenomenon that has been with humans since the earliest times. But it has become a topic of politico-legal philosophy only recently, and thanks to liberalism, for, as far as we in the contemporary world are concerned, it is liberalism that has continuously advocated that one is entitled to live the way of life that one thinks is fit for one's own life. Multiculturalism arises from the claim that immigrants (ethnic minorities) have their own ways of life that should be respected. It should be based on liberalism. The thesis is an attempt to delineate what the author has in mind about liberal multiculturalism. We shall find that liberalism has a built-in tendency to tolerate or respect 'alien' cultures or cultural practices. Multiculturalism, then, cannot allow any way of life to be at odds with its core: free and equal individuals. In a liberal multicultural society all people should support this principle. Other than that, anyone is free to engage in any activity or way of life. Multiculturalism, in one word, is liberalism in self-reflection.