Within the context of ethnic diversity and democratization, we start with the investigation of the legitimacy and desirability of designing a new constitution in Taiwan. After recognizing the imperative to synthesize political ideologies proposed to deal with the interwoven relationships among ethnic groups, the nation, and the state, we look into how nationalism, multiculturalism, and republicanism/constitutionalism may have enlightened us for constitution-making. Special attentions are paid to the choice of constitutional system and to the implementation of indigenous rights for the coming new institution. Finally, we will provide for a vision of multiethnic nation-state in Taiwan.