Since the import of Buddhism during Eastern Han Era, the Chinese culture has never ceased being influenced by Buddhism. During the Song Era, when the Neo-Confucianism rose and the Teachings were greatly stressed upon, more and more Buddhist scholars raised the ideology of combining the Three Teachings(Confucianism, Buddhism, and Taoism). On the history of the fusion of the Three Teachings, Yelu Chucai, the Minister of the early Yuan Dynasty, and an advisor to the Mongol Empire, started to govern with Confucianism, and thus established policies and achievements that Buddhist never were able to. The ideology of Yelu Chucai himself, with the fusion of Buddhist and Confucius Teachings, is well worth looking into. For this part of study, some scholars believe that he held the ideas of 'Using the name of Mohism, and practicing Confucianism', or 'Using the name of Buddhism, while practicing Confucianism', and there are still some, who considered him 'valuing Buddhism more than Confucianism'. This study no longer focuses on which Teaching (especially Buddhism and Confucianism) Yelu Chucai stresses upon, but believes and respects his idea that 'the Three Teachings originated from the same root'. This study believes he neither 'practiced Confucianism in the name of Buddhism', nor 'valued Buddhism more than Confucianism'; but acknowledges that he was a true Confucianism scholar, as well as a real Buddhist. His ideology of both was a combination of Mahayana's (a strain of Buddhism) world saving spirit, and of Confucianism's ideology of serving the world. And from the basis, has written off the conflicts between Buddhism and Confucianism. Yelu Chucai also focused on the practical issues and took the strength of Confucianism in policy, as well as the strength of Buddhism in personal virtue, and thus created a co-existence and co-relation between the two Teachings, allowing the Buddhist practices of the heart and soul to become the source of energy that tranquilised the heart, and feedback to the political ideas he held. Thus creating a wide spread state of peace, wealth and tranquillity in China.