This article tries to conduct research with its period of interest limited to the times from the US military government to the foundation of the Korean government in the horizontal dimension of the history of Korean language education under its awareness of the fact that work on Korean language textbooks since the National Liberation has been an important basis for the establishment of the identity and framework of the Korean language subject under the Curriculum led by the government. Moreover, in the sense that it initiates full-scale discussion of the structuring of the current grammar knowledge system in school grammar and contrastive analysis on the side of the structuring of the knowledge of grammar with the approved and certified grammar textbooks in the period of the American military government before the unified grammar and the foundation of the Korean government as its subjects, this article takes particles, alias Josa`s in Korean, as its subjects. Also, it tries to review changes in the methods of the description of particle-related grammatical categories through the comparison of the systems and descriptive methods in the grammar textbooks at that time with those in the grammar textbooks in the 7th Curriculum period. The process of actual analysis was divided into: 1) the level of part-of -speech classification; and 2) the level of individual part-of-speech description. Part-of-speech classification was again divided into postposition establishment, i-predicative particle establishment, existential predicate establishment, conjunction establishment, and predicative particle establishment, and individual part-of-speech description into verb, adjective, postposition, i-predicative particle, existential predicate, conjunction, and predicative particle problems. The analysis of the structure of the grammatical knowledge system related with particles in the grammar textbooks for the secondary education in the US military government period in which interest in the Korean language and grammar was extremely exalted after the National Liberation and diverse methods of the description of grammar were tried with the approval and certification system under the particular situation of the US military ruling is expected to contribute itself to the exploration of an effective structure of particle-related grammatical knowledge. Specifically, we can hope with this study to confirm the historical changes in the classification of particles, their semantic functions, explanatory methods for particles etc. Also, such exploration of the structure of the grammatical knowledge system related with particles is expected to have something to suggest to education of Korean grammar for foreigners as well as the development of grammar textbooks later and grammar for natives.