Multiculturalism is a method of national integration that aims to overcome the barriers between different ethnic groups and create a society of coexistence. In Japan and Taiwan, multiculturalism has been advocated since the late 1990s, but the history of its development and the means and objectives of its development have been very different. This paper redefines and compares the past aboriginal policies of the two countries based on the conceptual frameworks of assimilationism, cultural accommodation, cultural pluralism, and multiculturalism, and identifies the differences between the two countries. This paper analyzes the laws, constitutions, and governmental views on aboriginal policies that have been implemented in both countries, and clarifies the development of aboriginal policies in both countries and the differences in means and objectives.