The purpose of this article is to explore the social processes of ethnic mainstreaming and the possible role of the church. The author analyzes how Indigenous peoples gradually moved from the marginalized social stage to the social stage of ethnic group mainstreaming. First, the collective self-identification of indigenous peoples was established from the social movement and the collective self-determination campaign. Secondly, in the post-disaster reconstruction process, Indigenous peoples gradually developed intersubjective relationship with mainstream society. Thirdly, mainstream society gradually re-conceptualizes the idea of margin and center. For example, academic research points out that Taiwan is the homeland of the Austronesian Peoples, and the center is located in Taitung. Finally, Taiwan’s society has gradually developed the concept of ethnic mainstreaming ethnic. The author suggests that the role of the church in the mainstreaming of ethnic groups is to profoundly reflect upon the damage and harm done to culture in the process of evangelization. In conclusion, the author points out that the mainstreaming of ethnic groups should be understood as a special and crucial part of the overall transformational justice project in Taiwan. In addition to the setting up of nationwide policy, the reflection of the Church and the decolonization of mind are key elements for the implementation of ethnic group mainstreaming.