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. In the practical course of analysis, of the issues of 1) the distinction between particles and endings, 2) the classification of particles, and 3) the extent of the description of particle-related grammatical knowledge, the first in turn is addressed by ramifying it into problems ‘of the category of the particles and of Case,’ ‘of the establishment of Jijeongsa ‘copula’ or Jonjaesa ‘verb of existence,’ ‘of the establishment of conjunctions,’ and ‘of the distinction between adverbial particles and conjunctive particles,’ and the third into problems ‘of the presentation of phonologically conditioned allomorphs,’ ‘of the presentation of morphologically conditioned allomorphs due to changes in honorifics and tenses,’ ‘of the description of the aspects of the combination among particles,’ ‘of the description of grammaticalization-related contents,’ and ‘of the establishment of null morphs.’ 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.