AbstrakAgama Islam dianut oleh sebagian besar penduduk Kalimantan Tengah yang terdiri dari berbagai etnis seperti Dayak, Banjar, Jawa, Madura, dan lainnya. Penelitian ini mengkaji dinamika hubungan intern umat Islam dalam konteks relasi etnisitas dan agama di Kalimantan Tengah. Permasalahannya adalah bagaimana dinamika hubungan inten umat Islam, faktor pendukung kerukunan, dan strategi adaptasi membangun harmoni di Kalimanta Tengah. Penelitian ini dilaksanakan dengan pendekatan kualitatif dimana pengumpulan data dilakukan melalui wawancara, observasi, Focus Group Discussion (FGD), dan telaah dokumen. Hubungan intern umat Islam di Kalimantan Tengah diwarnai dengan tanggapan terhadap konflik etnistahun 2001 antara Etnis Dayak dan Madura. Faktor yang mendukung kerukunan yang tercapai saat ini antara lain adanya daya tawar budaya, simbiosisme ekonomi, peran tokoh masyarakat, dan peran pemerintah. Adapun strategi adaptasi yang dilakukan untuk memelihara harmoni dilakukan secara kultural dengan revitalisasidan akulturasi budaya dan nilai-nilai lokal, serta secara struktural dengan politik uniformitas baik yang dilakukan oleh pranata Adat Dayak maupun pemerintah Kalimantan Tengah.Kata kunci: Kerukunan, Budaya Dominan, Politik Uniformitas, Strategi Adaptasi AbstractIslam is professed by the majority of people in Central Kalimantan who consists of various ethnic groups such as the Dayak, Banjar, Javanese, Madurese, and others. This study discusses about the dynamics of internal relationship among Muslim in the context of the relationship of ethnicity and religion in Central Kalimantan. The problems are how the dynamics of the internal relationship amongst Muslims in CentralKalimantan and what factors are supporting to the reconciliation and adaptation strategies to build harmony amongst them. This research was carried out with the qualitative approach in which data were collected through interviews, observation, Focus Group Discussions (FGD), and document review. The results of the study showthat the internal relations among Muslims in Central Kalimantan was coloured by the responses to the ethnic conflict in 2001 between Dayaknese and Madurese. The study can also reveal that the factors which support to the achieved-harmony today are include the bargaining power of the culture, economic simbiosism, the roles of both community leaders and the local goventment. The adaptation strategies carried out to maintain the harmony were conducted in two ways: culturally (revitalizing and acculturating cultures and local values) and structurally (political uniformity which is performed not only by the social institution of Dayaknese but also by the localgovernment of Central Kalimantan).Keywords: Harmony, Dominant Culture, Politics Uniformity, Adaptation Strategies