The objective of this study is to examine the structure and transition of fertilization system in the 18th century. Especially, on the basis of this analysis, We can find the development of agricultural productivity in Chosun Dynasty. The improvement of fertilization method in the 18 century is found from all items -i,e-the time and object for fertilization, change of the concept in individual fertilizers. The transportation and the double - cropping of rice and barley in a paddy field had accomplished the improvement of fertilization method. Then, the development of agricultural productivity in a guarantee of higher fertilization method contributed directly to realize the consciousness of peasant's landownership.