In this paper, we clarifyed the words frequently and the relation between words and words used in the text of architecture by measurement text analysis. By doing so, we grasp important words and frequent contents: we named that “language structure”, beyond the individual sentence's commentary and author's personality, and clear the formation process by compare it each age. Because there is a close relationship between language and thought, the structure guided here will be an effective knowledge for architectural design.<br> The 40 years of text divided every 10 years, decompose and extract the text of each age into words. Measurement text analysis is performed on the occurrences of extracted words and the frequency of simultaneous occurrence in one paragraph. A word with the highest occurrences was taken as a “frequent word”, and the appearance trend by age was analyzed. In addition, those with the highest frequency of simultaneous occurrence of words and words in one paragraph were defined as co-occurrence, and “co-occurrence network” is drawn by connecting co-occurrence by lines. The co-occurrence network can be regarded as a linguistic structure expressing frequent contents by a group of plural strong words: high co-occurrence group, and expressing the centered word and the relation between words and words.<br> As a result of the above analysis, the findings obtained are mainly the following five.<br> 1) Differences in frequently occurring words in the work commentary are mainly caused by an increase or decrease in the occurrences of "all ages frequent words" at the top and a change in newly frequently occurring subordinate words.<br> 2) "Space" was the central position of commentary in all ages.<br> 3) A high co-occurrence group of a co-occurrence network is a group that mainly focuses on “space” containing a lot of words of concepts for creation and a group mainly focusing on "site" containing words of external elements in all ages it appeared in common. In addition, the group centered on the “wall” in the 80's and the 00's, the group centered on the “light” in the 1990s, etc. were seen as a characteristic group change. From the 1980's, concrete commentary conforming to the actual form of the building was on the increase<br> 4) Because the words and words in the co-occurrence relationship increased as approaching the 00's by increase of typical description method, commentary has been stylized.<br> 5) The contemporary language structure is formed by a group that does not expand and a group that expands by a stepwise process in which co-occurrence relationships already existed in the previous age co-occur with other words while continuance / compositing to have.