Organization of Islamic Cooperation is the second biggest organization in the world known as the Muslim representative in the world. OIC works to express Muslim voices and protect Muslim rights such as mentioned in the OIC’s charter 2008. Regarding to one of humanitarian issues or discriminations towards Muslim minorities that happened in Myanmar, OIC took a part in solving the issue. However until now the problem is still going on and condition of Myanmar has not improved yet. This things triggered a statement from the chief of All Pakistan Muslim League who stated that OIC became functionless and failed in protecting Muslim rights. This research used the theory of institutionalization by Samuel P Hunting to analyze the level of an organization and the reason why it became functionless and cannot solving Rohingya problem. Institutionalization theory is used to measure the level of an organization through adaptability, complexity, autonomy and coherency stage. This research was strengthened with concept of international organization by Holsti (1992) and Archer (2002) which explains the capacity of an international organization. According to the data, there are many obstacles which are adaptability of environment between subject and object, autonomy or political organization which does not support the subject and the last is coherency or cooperativeness between subject and object. All the aspects are the reasons of OIC’s limitation in addressing the conflict of Rohingya in Myanmar.