The purpose of this study is to analyze paejang system of the castle constructions In the late period of Chosun dynasty. Moreover, this study aimed to examine effects and influences of its constructional productivity. The results are as follow; 1. Paejang was originally a sort of military positions. Thereafter it had been adopted to the various fields like soonrapaes. Pae, which was a regular working unit organized with $30{sim}50$ laborers, took charge of the works allocated with its own chargeable section. 2. The first adoption of paejang system was found at the construction of Ganghwa-oyseong in 1690. Since the period of King Yeongjo and Jeongjo, it was generally used as a working system. 3. Yoo Hyeongwon had early suggested that this system should be adopted as a reformative system because it had a perfect command system like Soko-je, the provincial military system. 4. At the constructions of Dongnae-upseong, Jeonjoo-upseong and Daegoo-upseong in the period of King Yeongjo, paes were organized to $40{sim}60$units, and worked in the fields of masonry, carnage and picking of stones. 5. At the construction of Soowon-seong in the period of King Jeongjo, a large number of various paejangs participated in all of working fields. Especially masonry-paes were usually organized with over 100 units. 6. It was estimated that paejang system surely could guarantee saving labors and term of works. Moreover, it was a basis for the further development form of dogup-je, a contracted work system. 7. Paejang system was applied in the constructions of Buddhist temples since the middle period of 1700s and later, it was widely used in the constructions of palaces.