Jungshan Kingdom is Sun-woo's successor. The reason for this is that you can see this by looking at the names given to them in the records of historical books. In other words, it was mixed with Baekjeok and Seonwoo in the early days of Chunchu, and Seonwoo and Jungsan in the late Chunchu, and Jungshan was called Jungshan in the Jeonguk Dynasty, and it is said that Jungshan was named because there was a mountain in Junginseong Fortress where Seonwoo moved to the capital.
 Seonwoo and Jungshan first appear in Jwagumyeong's “Jwajeon” in the librarian's record. This period corresponds to the beginning of Choonchoo in 774 BC. It continued for nearly 500 years until the fall of the Jungshan Kingdom by the Zhao Dynasty in 296 BC. And in the Warring States Period, Jungshan had strong national taxes enough to be called Jeongook8ung in an era. Nevertheless, historical records such as “Jwajeon”, “Gookeo” and “Jeonrookchaek”, “Sagee” were recorded in fragments, Therefore, research on this was insufficient, and even the research relied on estimation, but there were many irrational tendencies.
 However, in the 1970s, the excavation of relics in Seokgajang area allowed us to confirm the reality of Jungshan Kingdom, and scholars' interest increased, and since then, research has been conducted from various angles. The paper also described the background of the formation of Seonwoo and Jungshan Kingdom, the reality of the people, the location of Junghsan Kingdom, the rise and fall of Jungshan Kingdom, and until the Jungshan after the fall, I tried to approach and understand the reality of the middle mountain country with universality and rational description. A summary of the contents of this paper is as follows.
 The first is to find out who they are. In this regard, Yang Ok-seung, who denied the theory of being a descendant of the Zhou Dynasty, but insisted on the theory of Baekjeok, agreed and followed it. Regarding the reality of Hanjok and Dongijok, it helped to understand by publishing “Oje and Ha, Eun, Ju's Sijo Genealogy” by the Sagi Research Institute of the Hangaram Historical and Cultural Institute, which identified this.
 Second, where did you live? It is believed that Baekjeok established power in the current Seomseo and Naemongo areas north of Sanseo and entered the Sanseo and Habuk areas beyond the current Sakju and Anmungwan, and the period of movement was before 774 BC.
 Third, it is 'the varied fortunes of races.' of Jungshan Kingdom. From the study of Jungshanmungong to the time when the last monarch 'Sang' was conquered by King Muryeong of the Zhao Dynasty, Mugong settled in Go, and the twists and turns of Buchim continued, but at one time, the national tax was strong enough to win the title of the king.
 Fourth, after the fall of the Jungshan Kingdom, we looked at the path of the name Jungshan from the Qin Dynasty to the Tang Dynasty. The name Jungshan was maintained as an administrative unit of Hangsan or Sangshan, but the name Jungshan was generally used.