Abstract: Existency of the Elements of Traditional Law in Indonesia Islamic Law Compilation (KHI). This paper reviews the accommodative attitude of the Indonesia Islamic Law Compilation (KHI) towards customary law. Such a positive attitude is indicated by the provisions concerning joint property and mutual inherit between adopted child and the adoptive parents through the institution of wasiyat wajibah. (compulsory wish). Both provisions adopted from customary law is purely the result of ijtihad (legal initiative) of Indonesia Muslim scholars because the issues are not found in Islamic Jurisprudence. The Indonesian cleric’s innovative creations, aside of being a manifestation of the dynamic and creative characteristics of Islamic law, are a...