This article discusses the state of the rural defense in the late Chos?n, problem and its various tasks, then investigates the usage of Dasan’s Min Bo Ron as the official National Defense system. Chos?n’s military system was traditionally carried out with a focus on the Central Guard. The reason for this was that state desired establishment of a Centralized system by a strong Central Guard. This policy was fixed by the completion of the Five Military Corps in the late 17th century. But, the policy brought about the weakening of the Local Military Forces. Due to the aggravation of the National finance, the purpose of the Military Service System was preferred for the reason of taxation rather than for the reason of the national defense. Also, as threats from outside decreased, concerns about Local Military Forces became less important. Moreover, Military Posts system was initially made to look after training of Sog’o militia. However, it often resulted in confusion of the Military Command system and brought about several ill-effects both to the military and the people. Measures for the rural defense were urgently desired in situations where Sog’o militia and Military Posts system caused a nuisance to the people and lost its military function. Under these circumstances, two opposing issues on the Rural Defense Policy were raised. The first was argued by the government officials called the “No-ron”. They regarded the weakness of the Local Military Forces was caused by mismanagement of the Military System. They also argued that problems in the management should be corrected and improved or to reinforce the Rural Defense by training the Local Government Officials(Suryong)’s Personal Guard. These arguments had limits because it was not based on the desire of the land reform by farmers’ Principles of Farmer-soldier Service(byeongnongilchi). The second was argued by Confucians called the “Nam-in” in the opposition. They found the cause to be the lack of a basic reward system. Therefore, they wanted to make an attempt to reform the Military System which was based on the farmers’ land ownership. In addition, they wanted to defend the rural areas by combining the Local Organization and the Military Organization. These arguments also had some limitations in that it is not able to remove a social status of a noble family. The above mentioned arguments remained as problems of the Rural Defense Policy. Also, the Rural Defense Policy in the 18th century was very general and superficial because it was formed while the state of the foreign affairs was steady. Moreover, this policy considered Cheong to be more of a military threat than Japan. However, in the late 18th century Japan’s hostility toward Chos?n was becoming bad to worse. As the western influence began to strengthen, Japan put forward the idea that the invasion of Chos?n was necessary in order to protect themselve. In reality, the Friendly-neighbor Policy between Chos?n and Japan had already come to an end at the time. So, Chos?n had to make sure to set up a solid defensive measures from an attack from Japan. However, Se-do Government in the 19th century was abandoning such responsibilities. Defense against Japan’s attack was becoming a problem at the time. In the face of these difficult military problems, Dasan Jeong Yak-Yong put forward a solution in the『Minbo?i』in his book which the Rural Defense Discussion was intensely included. Through the management of Public Defense(Min Bo), he desired to preserve the life of people and property. Also, he wanted to defend the country by cooperating with the government forces as well as to stabilizing the existing Local society. This Dasan’s Public Defense Discussion(Min Bo Ron) standed on the confidence about the people in that it is based on the people’s arm that put under taboo. In addition, the style of electing people by ability, managing an organization by unbiased view can predict that Public Defense and is consists of a rational and democratic organization. The total capacity of the Public Defense may be multiplied by duty assignment and a part assignment of specialization. Then Principles of Farmer-soldier Service’s community life except privilege of a social position can increase production, military activity’s efficiency and strengthen a Public Defense’s unity. Above all, this was a proper plan to reduce finances burden and can be policy to stop insurrection of the people. The realistic organizational basis for the Public Defense System may have been active using local self-government structure like a Hyangyak or Lin-Bo organization. On the other hand, Dasan’s Public Defense Discussion(Min Bo Ron) needed the armourment of people. It required the removal of statesmen’s distrust and deliver their decisions. However, as the first half of the 19th century was Se-do Government period, the statesmen didn’t permit Public Defense Discussion(Min Bo Ron) that can break up military power and didn’t have a will to elect the Public Self-Defense System either. But, as Dasan’s Public Defense Discussion(Min Bo Ron) was still considered useful, his ideology was continually developed towards the direction of increasing the use of firearms appropriately. Since the 1860’s, as the western influence was realized, the Public Defense Discussion(Min Bo Ron) was attracting much attention in the royal court. Sin-Heon the follower of Dasan also received strong trust from Taewongun at the same time, claimed the Public Defense’s operation. As a result, the Public Defense Discussion(Min Bo Ron) was implemented to be the Nation’s Official Defense policy in 1867(Year 4 of Go-Jong). But, in spite of Taewongun and Public Defense claimant’s effort, the nationwide practice of the Public Self-Defense System failed. The reason was that the critics of the Public Defense establishment obstructed an overall practice because they thought that the Public Defense brings out a social unrest and become the reason for the collapse of local society. However, at the end of the 19th century, as Chos?n government needed the establishment of the Public Defense system. Efforts for nationwide practice was being continued. Moreover, as this period was a point of time when the most systematic and massive peasant uprising was prepared, it was felt that local defense was essential more than at any time. This Public Defense Discussion(Min Bo Ron) may have been an aid in the search of the Gabo Reforms’ period, the end of the Korean Empire military system reforms and the establishment of independent Modern State establishment. As a result, since the discussion of the of Public Defense Discussion(Min Bo Ron) in the 19th century, the power of the military became an origin which promoted the Righteous Troops Activity and the Revolutionary War under the Japanese regime.