Koguryo had contacts with various non-Chinese people in north China as well as Chinese dynasties, which is natural considering Koguryo's geographical situation. Therefore, when one examines the foreign relationships of Koguryo, not only those with China but also those with non-Chinese people in the north have a significant meaning. In this paper, by examining how non-Chinese people including Xianbei, Qidan, and Rouran perceived Koguryo, I shall suggest the significance of Koguryo in East Asian history. In addition, I will investigate how the relationships between non-Chinese people in north China and Koguryo influenced on the international circumstances in East Asia. The contacts between Xianbei and Koguryo began since the common era. The actual contact was from when Murong Xianbei advanced to the Liaoxi region. According to Samguk sagi, Murong attacked Koguryo in 293 and 296 AD. The reason why Murong attacked on Koguryo is not certain. Considering the fact that Murong competed with other Xianbei tribes, Murong might have considered Koguryo as one of threatening powers. It is assumed that Murong attacked Koguryo in order to prevent Koguryo from interrupting internal conflicts among Xianbei tribes. As it moved to the 4th century, Koguryo competed with Murong in the Liaodong region. In 341, Murong established the Former Yan, and tried to expand its territory to the neighboring regions. In the next year, the Former Yan attacked Koguryo and seized Koguryo's capital. It is notable in that the purpose of the attack of the Former Yan was not on oppressing Koguryo, but cutting the ally between Koguryo and Yuwen tribe, and then finally destroying Yuwen tribe. Thus, the ultimate goal of the Former Yan was actually to gain the access to the Central Plain region. The Former Yan considered Koguryo as a threatening power, and the development of the nation depended on the success on the foreign policy against Koguryo The Qidan people who establised the Liao appeared in a written record from the late 4th century. According to Samguk sagi, Qidan invaded the border region of Koguryo in 378 in the 8th reign year of King Sosurim. King Kwanggaet' o campaigned against Qidan right after ascending to the throne. By the late 5th century, Qidan got influenced by the advance of Koguryo to the region of Hsiramulan river. In 479 when Koguryo and Rouran conspired together in dividing Didouyu At this time, oppressed by Koguryo, Qidan got incorporated into the Northern Wei. After the Sui dynasty established, some Qidan who were under Koguryo and Turks were absorbed into the Sui. Qidan got stronger by the late 6th century, and developed into the 10 tribes' confederation. The unification of the Sui brought the stability in Chinese territory However, a tension rose between Sui and Koguryo who competed for the hegemony in East Asia. As a war broke out between Sui and Koguryo, Qidan participated in a war as subsidiary troops. Qidan did not have an opportunity to have a political development or power expansion under the pressure of Koguryo and Chinese dynasties. Thus, it was impossible to act independently with its own identity. Rather, Qidari s existence depended on the political situations of powerful nations around it. In the Northern and Southern Dynasties, Rouran gained power in the northern region of China along with the Northern Wei. Rouran allied with Koguryo in order to restrain and isolate the Northern Wei. In addition, Rouran allied with Koguryo in dividing Didouyu region in the effort to prevent the Northern Wei from exchanging with other countries. Rouran considered Koguryo as one of powerful nations in East Asia, and allied with Koguryo to isolate the Northern Wei. The international circumstance in East Asia by that time showed the balance of power among the Northern and Southern Dynasties, Rouran and Koguryo. In summary, the non-Chinese people in north China considered Koguryo as an independent power different from China, and perceived Koguryo as a restraining party or allied party according to their political situations.