The purpose of this study is to examine Park In-ho’s leadership succession process as one of the organizational institutionalization processes of Donghak and Cheondogyo, and to confirm that this process allowed the reconstruction of Donghak and Cheondogyo and various activities of Cheondogyo afterward. The contents of this study revealed that the process of changing from Donghak to Cheondogyo was a process of institutionalizing religion, and during this period, Park In-ho’s activities were confirmed to be in the stage of education and training of successors and mutual cooperation with previous leaders. Since then, it has been confirmed that the educational movement, cultural movement, and independence movement of Cheondogyo have been possible because they have achieved the institutionalization of religion, and the role of Park In-ho, who directed it, was important. During this period, it was confirmed that Park In-ho’s activities were in the stage of mutual cooperation and leadership transfer during the leadership succession process. It was after Son Byeong-hee’s death that the leader’s relocation concluded, and Park In-ho continued to direct various activities, protect the organization, and unite the church members as the leader of Cheondogyo. The results of this study revealed that Park In-ho’s succession to the leader of Cheondogyo was also an important period in the Cheondogyo organization, and his role and activities in the process were based on various activities, including the independence movement. Although Park In-ho is not a charismatic leader like Choi Je-woo, Choi Si-hyung, and Son Byung-hee, he can be defined as a person who has completed the institutionalization of religion, routinisation of charisma and demonstrated leadership based on rationality according to the system.