Abstract: In the historical trend that different ethnical groups began to build their own regimes after the disintegration of the great union of the Easter Jin Dynasty, Baekje represented a typical performance. With the tianxia Consciousness, Baekje formally constructed a unified political system and shared a same cultural world with the Eastern Jin Dynasty. The reason why the King of Baekje obtained a title in Baekje’s first presenting tribute to the Eastern Jin lies in the international situation and respective domestic demands at that time on the one hand and the fact that the king family of Baekje was the offspring of Buyeo on the other. Since then, almost each King of Baekje sent an envoy to the court of the Eastern Jin and Southern Dynasties to accept the former king’s title at the beginning of his reign. In the 5th century, especially after the King Dongseong submitted to the imperial court, it became a usual practice that the officials in Baekje must be appointed by the court of the Southern Dynasties. Compared with King of Dangchang and King of Henan, King of Baekje enjoyed special privileges from the imperial court in terms of absorbing the culture system of the region of jiangzuo due to their cultural and emotional identity. Baekje and the Eastern Jin and Southern Dynasties shared the same tianxia order, and the decline of the Southern Dynasties also caused the decline of Baekje.