When we analyzed the myth about the founding of old Chosun`s, which comes out at the beginning of Samkukyusa, We can see that our korean people was descendant of which his ancenstors(ancestors) believed in heaven`s gods, and it we read Japanese myth, what we can "Kiki Myth" which is on the establishment of Japan, we can also understand that Japanese people was the descendant whose ancenstors believed heaven`s god. As above mendioned, Korean and Japanese peoples, were the same descendants of peoples who had believed in heaven`s gods. Then how had their nations related? I propose the following views about the problem mentioned about. First of all Tangun Wonggeom established Tangun Chosun at the East area of Liao River region about BC 2300. About BC 12 century, which was the end of Sang(商) Dy nasty and the beginning of Syu(周). On of Tangun Chosun`s descendants growed out into Dongho(東胡) which was the most powerful country at Liao River region at those times. But it was ruined at BC 206 by the second king, Sunwn Mukdol of the Huns Empire which was of constructed in Inner Mongolia. I suggest that we should understand the collapse of Old Chosun was the ruin of Dongho. As the result of Dongho`s collapse, separated Dongho`s people into three parts. One entered the Huns Empire in the west of Liao River region, another went out towards. Buyeo(夫餘) region in the east?north areas of Liao River region, and the others remained in the base where Dongho people had lived for long times. What I emphasized here is that Jinkuk(辰國) came from the last part, and Gokuryeo(高句麗) came out from the Jinkuk. Also Baeje(百濟) established at the middle part of Korean Peninsula in later part of the first century BC, came out between Buyeo and Gokuryeo. Byeonhan, one of three Han(韓), had been established at the lower part of Nakdong River, in the last of second century of B.C by Jinkuk`s people who came down to south part of Korean Peninsula. At the affer of fourth century, Baeje of horse?riding people accepted a mock cavalry culture from northern horse?riding people. Baeje had relationships which Gaya(加耶) which Byeonhan had turned into. The King of Gaya`s moved to northern Kyusyu at the latter of century, and dominated the country called Wae(倭) established at the northern Kyusyu. At the latter 5?4 century the country of Wae, unioned with Baeje occupied. Yamato area, and unified northern Kyusyu and Yamato area, affer the established. Yamato Government as far as we concern with the historical facts mentioned above. We can not but accept that descendant of Dangun Chosun established Yamato Government.