Since the foundation of the nation in 1830, Belgium has faced the confrontation between Flemings and Wollons, who have immense difference from one to another in aspects of languages, religions, cultures and economic development. As Flemish nationalist movement grows, three kinds of identities, which are Belgian state identity, Flemish identity and Wallonian identity, have emerged, mutully inflenced and become the most significant factor to domestic politics of Belgium. In order to solve the high domestic divergence, the four constitutional revisions started from 1970 has transformed Belgian political system from model of unity to regionalism, and eventually, to federalism. After the fourth constitutional revision in 1994, Belgium has become an unique federal state, composed of three communities are divided based on languages and cultures, and three regions based on economic performances. The revised constitution havs been used as an approach to reduce conflicts among ethnic groups, and it also instutionalized interests of each groups. This thesis adopts historical approach and literatures reviews as methodologies, and tries to ask three questions. First, how the three identities influence each other? Second, How Belgium deals with ethnic conflict with a moderate process? And third, what is the influence of the new political design? How this influence works to the social values?