Laggai government is a form of government based on “Arat Sabulungan” in the Mentawai Islands whichrefers to ethnic identity based on racial equality, religious ethnicity, origins that are bound in the culturalsystem to conduct self regulation; regulate and manage customary land, territory and traditional heritage.
Mentawai is one of the ethnic groups that obtained policies on behalf of the state to implement moderngovernance such as the nagari government system, village government faced various forms of moderngovernment such as Desa, Nagari which was forced to be applied in serving the people in Mentawai, whichhad implications for the existence of the original Mentawai government which was eroded. and does notwork.This research is intended to determine the relationship between Laggai government in Mentawai andmodern government which operates through governance practices. In addition to this, the authors revealthe clash and conflicts that emerged as a response to the implementation of modern government. This studyuses a behavioral approach (governance). that is, gathering and gathering all tacit knowledge in order toread the self-regulatory arrangements that have long been the character of what is called government bythe Mentawai people. The study concludes that the practice of modern governance in Mentawai presentspower struggles and clashes. The power struggle eventually led to conflict in response to the presence ofthese modern government practices. Democracy and decentralization is a space for the Laggai Governmentin Mentawai as a form of recognition and appreciation from the state so that the Laggai Government inMentawai has the maximum function to conduct self-regulation to the community