This study was based on interest in authority detection in Domestic Litigations and the roles of the person concerned in such litigations. The court's power of authority detection should be interpreted to be accompanied by duties. Considering the subjecthood of the person concerned, the court needs to admit that its authority detection is not without limitations or restrictions but does have some limitations. In interpreting and applying the Family Law Litigation Act, both the sides must be considered; one is that Domestic Litigations belong to the case category that requires the court's guardianship called authority detection; and the other is that the intervention of public power should be avoided as much as possible since they involve highly private matters. Thus the right ways to go are to exercise authority detection thoroughly where guardian interventions are required by analyzing the case and to interpret and apply authority detection as supplementary where the concerned person's right to deal with the issue is approved. Under authority detection, it's natural that the concerned person's right to procedures must be secured and that the court should not be allowed to recognize as facts the matters about which the concerned person was not given a chance to refute or make an excuse. The next revision of the Family Law Litigation Act should newly include a provision of informing the parties interested of the litigation materials collected by the court and providing them with a chance to offer their statements so that they can prepare themselves for defense. Finally, the following suggestions were made for the revision from the perspective of legislation: Article 17(authority detection) : ⓛ When examining Domestic Litigations of GA class or NA class, the family court must look into facts and gather necessary evidence and can ask for cooperations from the person concerned. ② The family court can take into consideration of the facts not argued by the person concerned and interrogate the person concerned or his or her legal proxy any time. In such a case, the family court must listen to the opinions of the person concerned regarding the facts and the results of evidence gathering.