This thesis examined the methodology of historical research of Ota Kinjo known to be the authority of Japanese methodology of historical research in the development process of the study of Confucian classics by returning it to the internal problem of Japanese history of thought. Kinjo made the restoration to Confucius and Mencius as the task and concentrated his energies on thorough historical research of the Confucian classics in the process returning to Confucius and Mencius. In this process, Kinjo pursued edification from the inside of individual heart and the big characteristic of Confucianism of the second half. It should be noticed that there was thorough historical research of the Confucian classics in the background leading this.