The position of adat court in Indonesia civil legal system has a long history. Distinction of public or private sphere would appear when adat court decisions in contact with national judicial system. Interaction between both systems isn't ideal, either at the level of norms and practices. Unification policy of judiciary institution is one cause which make adat court was forgotten. Although the Judicial Authority Law opens possibility of resolving civil cases by agreement based mechanism, it requires the various perspectives both of legal-normative regarding the existence of adat court and the law implementation prespective regarding Indonesian civil justice system.