The research objective is to determine the form of strengthening the role for a customary institution through the preservation of legal knowledge on maintaining the survival of the Moronene Hukaea Laea Indigenous People and to determine the effect of strengthening for the role of a customary institution on the preservation of legal knowledge on maintaining the survival of the Moronene Hukaea Laea Indigenous People. This research uses descriptive qualitative with empirical normative approach. The result of the research is a form of strengthening the role of traditional institution through preservation of knowledge on maintaining the survival of the Customary Law’s Community Moronene Hukaea Laea, which is to routinely carry out tradition or traditional ceremony that has been passed down from old generation to young generation, including ceremonies for releasing the harvest and welcoming the planting year (mewusosoi), a ceremony to request permission from supernatural beings who guard the forest (ntiwonua) before land clearing (mo'ooli) and village purification ceremonies (montewehi) as well as supervision of customary institution for customary violation which it can be sanctioned by the customary institution according to customary rule. The influence of customary institution on the preservation of legal knowledge for maintaining the survival of the Customary Law’s Community of Moronene Hukaea Laea, includes influence internally and externally. The influence of strengthening the role of customary institution internally, can improve the welfare of indigenous people. It can protect the existence of indigenous people.