Yung-he-ti is the third emperor of Ming Dynasty in the fifteenth century. He was a man who took a very active part in the national and military affairs in the vast area. His educational policy had necessarily to extend over the vast area. Here I wish to describe how he planned and practiced the policy over such an area as came under his control or over foreign lands. He decided without permission that Japan and Loochoos belong to him, and yet their rulers so much wished to have a foreign trade with his country that they were not so particular about the problem. So he believed it his duty as a great ruler to enlighten Japan and Loochcos and printed a hundred enlightening books, "CH'UAN-SHAN-SHU" and "NEI-HSUN-SHU", in order to give them to Japan if it wished to have. He welcomed students from Roochoos and gave them facilities for their study. He established a school in Yun-Nan district where many people different from Han race were living. Young people of powerful families rooted in that district were invited to enter the school in the capital, but he never took advantage of them as a hostage, thus showing an emperor's magnanimity of a big kingdom. Moreover, he dispatched a large expedition army to Viet-nam and conquered it. Many schools were also established there for the purpose of cultivating humanity by the Chinese culture, fostering officials, and enforcing them Chinese style of government. Thus Yung-le-tis educational policy was fundamantally of imperialistic character with the background of military power, but it must be noted that he had an intention of enlightening the uncivilized area. Of course it was based on the idea of Middle Flowery Kingdom, the best center of the world, but it was an innevitable matter at that age when the ideal of formation of humanity could not pass a certain limit in Asiatic world.