Abstract
In this paper, the occurring process of terminology in junior-high and high school science textbooks has been analyzed. I extract index terms from the body text of textbook, which I consider as terms that represent main concepts in textbooks. Then I visualize and describe how new terms appear, and how they are repeated from the beginning towards the end in the body text. The primary results are as follows: (1) New term appears constantly as a whole, while many more new terms appear in some sections. (2) The degree of concentration of frequency distribution (i.e., few terms are repeated many times and many terms are repeated few times) are more and more strong as a whole, while it rapidly increases in some sections. These results differ from the results obtained when terms appear randomly in the texts. In addition to that, some characteristics of each domain, school year and period are also observed.
