This study is an investigation that explication of the reading method of transcription marking, and explains what it means and where to use transcription marking of architectural vocabulary. focusing on timber class vocabulary from on SeoGwolYeongGeonDoGamUiGwe(${\ulcorner}$西闕營建都監儀軌(1831)${\lrcorner}$). This study is reviewed sequentially classifying items according to timber class, stone class, iron class architectural vocabulary. This treatise, named 'Architectural Vocabulary Study (1)', is mainly focused on making out a transcription marking of timber class vocabulary on the documents. But, because of the properties of the UiGwe(儀軌), there are some different expressions used for the same vocabulary. Therefore, the different expressions are referenced according to vocabulary used from the 17th century to the 20c century. This study lists timber class architectural vocabulary of transcription marking on SeoGwolYeongGeonDoGamUiGwe(${\ulcorner}$西闕營建都監儀軌(1831)$\lrcorner$). This study also explicates and explains the meaning of them. In advance, this study compares them with the vocabulary of national language in the middle ages and modern times. If we could explicate the transcription marking of the documents as it is, we can't only recover plenty of vocabulary related with characteristic architecture in the age of later Chosun Dynasty, but also correct wrongly used vocabulary nowadays. With the results, we can standardize and adjust vocabulary use of Korean traditional architecture. In advance, we can correct errors of spelling and mistaken explanation in the Korean Encyclopedia.