The year 1609, when experience and awareness of Yu Mongin on the road of diplomatic travels to Beijing reached the peak, is about the middle point in the 700--year`s history of diplomatic travels to Beijing. It is the time when East Asia reorganized its political order and Ming dynasty was replaced by Ching dynasty in China. Joseon needed to urgently reflect its administration and find out new ways for survival and sustainability as undergoing Imjinwaeran(Japanese invasion in 1592) and Byeongjahoran(Manchu war in 1636). Yu Mongin believed that Joseon overcame the national crisis by progressively learning the systems and culture of Ming dynasty. The road of diplomatic travels to Beijing means the cultural rebirth to him. His diagnosis and measures to social ills of Joseon dynasty were urgent, progressive and realistic as much as the diagnosis and measures by Bukhakpa(northern learning faction) scholars in late 18th century. Nevertheless, the awareness of Joseon dynasty on CHina was very superficial and restricted. While there was a number of reasons for such awareness, one of the main reasons was that Joseon society failed to cultivate the responsible experts on China. In such circumstances, the notional knowledge on China was saturated and so interrupted proper understanding on others and self-awareness. Yu Mongin who showed the best knowledge and awareness on reality in his period was not an exception. Yu Mongin saw only the absolute importance of road of diplomatic travels to Beijing and superiority of Chinese civilization but completely failed to recognize the change of road of diplomatic travels to Beijing by others and historical upheaval in the near future. He also couldn`t go beyond the limit of "Notional Past" in the recognition on China. Yu Mongin`s awareness on road of diplomatic travels to Beijing demonstrated that the efforts of Joseon and its choicein early 17th century were failed. The road of diplomatic travels to Beijing has both openness and closeness at the same time. We could have improved the civilization level by continuously accepting the news from the world as well as advanced culture of China through the road of diplomatic travels to Beijing for about 700 years. The road of diplomatic travels to Beijing was the path where the driving force forming the civilization of Joseon was delivered. The road of diplomatic travels to Beijing was the path linking Joseon to the world. On the contrary, the road of diplomatic travels to Beijing was also a blocked path. Since there were no roads to the world except the road of diplomatic travels to Beijing, we would be alienated from the world if the road was paralyzed. However, even that road was ended in Beijing. The road was the same as a dead alley because we didn`t have courage or qualification to extend the road. If we compare a road to a blood vessel, the road of diplomatic travels to Beijing was the blocked blood vessel. The unconditional dependence on such a closed road was the reason for the failure of Joseon dynasty in early 17th century and why Joseon dynasty couldn`t keep pace with the world in the 19th century.