Studies on Old Joseon by the North Korean circles of history had experienced great changes from the previous Yodongjungsimseol to Pyeongyangjungsimseol after discovering the tomb of Dangun in 1993, with regard to theories of Old Joseon’s main territory. According to the Pyeongangjungsimseol, the main territory of Old Joseon was Pyeongyang, not Yodong and the oldest estimated age traced back to B.C 30 century from B.C 10 century. The North Korean circles of history names it as “Daedonggang Culture” and insists that it was one of five ancient civilizations. After the year 2000, it keeps supplementing and enhancing Pyeongangjungsimseol with publication of archeological evidences and appearance of new researchers. The archeological outcomes that support Daedonggang Culture including a group of dolmens, house sites in the era of spinning top shape pottery, gourd shape bowls, fortress and prostrate has been published in the literature such as “A Series of Joseon Archeology” (Ancient Times) and “A Journal of Joseon Social Science” (Archeology). However, it is problematic that they also increase the oldest estimated age of other areas, while insisting that mandolinshaped bronze daggers and Misonri-type pottery, which are both the famous well known Old Joseon’s relics, originated from the Pyeongyang area. The literature study pays most its attention to diversification and territory of Old Joseon before and after its establishment. In addition, new researchers like Jeon Dae Jun and Choi In Cheol are actively involved in publication of relevant study. “Joseon Dandaesa: the History of Old Joseon” (2010), the co-work of both researchers, shows new trend of study. The period when the early Old Joseon and the late Old Joseon was established are redefined to the early B.C. 30 century (B.C 2993) and the middle B.C. 15 century (B.C 1466), respectively. With regard to the relationship between the country and neighbouring countries, the book understands that the culture and governing system of Buyeo, Guryeo and Jinguk are similar to those of Old Joseon because they were the independent countries which consisted of the same ethnic groups to those of Old Josean and were marquisates of the early Old Joseon once. This book emphasizes that Goguyeo is the legal descendent of Old Joseon, which succeeded to the territory, people and even the capital of Old Joseon with its historical status and roles. Although the excavation of Dangunreong and argument of Daedonggang Culture creates many issues, they have strong mythological elements. Such difference between South and North Korean researchers' perception with regard to Old Joseon, the oldest country in the history of Korea, should be converged with joint investigation and academic exchange.