This study aims to determine the strategy of the Adang community's customary institutions in maintaining and preserving regional culture, especially the belis culture. This research uses descriptive qualitative method. Data collection techniques using interviews, observation, and documentation studies. The research results show thatthe strategy of traditional institutions in preserving belis cultural values is to continue to carry out adat according to the procedures or customs of the Adang people. Based on the data obtained from the field and the analysis described above, the values contained in the belis culture in the implementation of traditional marriages are as follows: Sahol Maeh sey Alepang (Knowing each other), Fang Abul (Honesty), Ada aholhormat (Mutual Respect) , Uli (Courtesy), Tenagel (Brotherhood), Tolerance, Bang Om (Family), Sadel en (Responsibility), Tey ta ta (Gotong Royong), Religious, Appreciate, Lamuil (Courage), keep it well maintained. The strategy carried out by traditional institutions so that the values contained in belis are well maintained is carried out in 3 ways, namely: simplifying by reducing the beneficiaries of belis goods, simplifying by replacing the main belis with other types of moko, simplifying with just two moko, simplifying with just one moko. Meanwhile, the obstacles faced by the traditional institutions of the Adang community in implementing the strategy for preserving belis culture are (1) the lack of understanding of the community in interpreting the values contained in belis culture and belis goods which are increasingly difficult to obtain. (2) Lack of coordination between all interested parties between the village government and customary institutions. (3) the unpreparedness of the male family in preparing belis goods. While the obstacles faced by the traditional institutions of the Adang community in implementing the strategy for preserving belis culture are (1) the lack of understanding of the community in interpreting the values contained in belis culture and belis goods which are increasingly difficult to obtain. (2) Lack of coordination between all interested parties between the village government and customary institutions. (3) the unpreparedness of the male family in preparing belis goods. While the obstacles faced by the traditional institutions of the Adang community in implementing the strategy for preserving belis culture are (1) the lack of understanding of the community in interpreting the values contained in belis culture and belis goods which are increasingly difficult to obtain. (2) Lack of coordination between all interested parties between the village government and customary institutions. (3) the unpreparedness of the male family in preparing belis goods.

Keywords : Customary institutions, belis.