This research examines the istinbath construction in the Indonesian Supreme Court’s inheritance law jurisprudence, which has resulted in the emergence of conservative groups who criticize inheritance fiqh because their findings contradict classical Islamic law. This research is a qualitative descriptive study using a legal-contextual approach to pluralism and Menski's triangular. The results show that the Supreme Court's jurisprudence applies the Transformative-Universalism concept, which uses ijtihad intiqa'i and extra-doctrinal technical building methods of legal reform. According to Menski, the reform of fiqh law can be carried out in three forms: 1. Paying attention qath'i in inheritance law which has Islamic-philosophical values; 2. Expanding the formulation other than the qath'i by taking into account the sociological values of society and its customs, as well as the substance of maslahah in it; 3. Carrying out legal-formal reform through fiqh with philosophical considerations of Islamic law and empirical (customs and social reality).