This study analyzed the main bodies, sizes of litters, spaces between letters, Words, lines, length of lines, sizes of main body and margin, Position of the main bodies of PDF(Portable Document Format) in high schools and "the criteria of reading system for the textbooks" which was suggested by the Department of Education and Provided some suggestions for the improvement. First, it is judged that spaces of the main body of textbooks should be shrunken to make the ratio of 50:50 between the main body and space margin. Second, it is judged that the main body should be placed in the center of text page. Third, the results of the above findings showed that it would be difficult to deal with the task of deciding space and position or the main body and marginal space in a form of single project, because there are many variables involved and psychologically complicated elements which can not be measured objectively.