||The objective of this article is to re-establish the relationship of political marriage for peace treaty between Baekje and Yamato Wa. Political exchanges of royal family between Baekje and Japan had persisted until the fall of Baekje since the year 397 of the King of Asin. According to the analysis, for a while Baekje and Japan had broken off diplomatic relation during the reign of King of Biyu, King of Samgeon, and period of the late sixth century. But still, their mutual exchanges between the two countries kept appear until the fall of Baekje, indeed sending Pungjang. The analysis about the royals said, their exchanges from these two countries was usually found through marital relationship. Generally, conventional wisdom from Japanese academic circles maintained that the hostage diplomacy between Baekje and Yamato Wa is just political and military subordinate to Japan as like a dominant-subordinate relationship. However, this article show that Japanese academia's opinion doesn't hold water when it comes to a situation like this Baekje and Yamato Wa seem to keep their culture and more exchanges based on this marital relationship after the age of Ashin king. In addition, they can keep their political or military relationship as friendly through this personal exchange. Therefore, Baekje accomplished extending pro-Baekje influence in Japan furthermore, expanding pro-Japan power in Baekje as well. We could observe that the relationship between Baekje and Yamato Wa was their cultural exchanges by marriage between the two royal families and that the transmission of advanced civilization from Baekje to Yamato Wa corresponds to support of Japanese military power to Baekje. Therefore, relationship of Baekje and Wa has to be figured out as keeping eyes on diplomatic relations according to the marriage in East Asia at that moment.