Law of Marriage which constitutes a product of Indonesian people regulating any aspects of marriage into a regulation for any Indonesian people, this is not to say that this regulation is perfect and away from any legal issues, one of which is interfaith marriage, with the uncertainty of interfaith marriage law in Marriage Law results in different verdict particularly in interfaith marriage registry in Indonesia. This study used a legal research method and this study used approach methods namely historical, conceptual and legislative approach. Legal entities used in this study include normativeprimary, secondary, and tertiary legal entity which was applied in the manner of observation, collection and literary study of document either conventionally or through internet. Study results on interfaith marriage held in Indonesia suggested that neither the Religious Affairs Office (KUA) nor the Population and Civil Registry Office (Disdukcapil) shall accept it. Despite interfaith marriage in Indonesia has been set out in Law of Population Administration (Adminduk) and registered in Indonesia, as it is tied to stipulation outcome of District Court. Should the district court grant the request of interfaith marriage, then the Population and Civil Registry Office shall report interfaith marriage and otherwise.