This article is focusing on the importance, concepts, and theses of Military Thoughts. This article also tried to find the research trend on the Korean Military Thoughts History. In addition, this article makes a general overview of Yang Seong-ji in the mid 15th Century. The fundamental objects of Military Thoughts are Tactics of a person for Military Affairs and Military Tactical Manuals. The circumstances at that time, the Military System, and Weapon system are based on the preceding two essential elements on Military Thoughts. From now on, this article insist on the necessity of the Study on the History of Korean Military Thoughts focused on a military figure.