The reading materials in the English textbooks for Japanese high school students are often the rewritten version of the originals. In many cases, post-reading activities are added to those adapted materials. The purpose of this paper is to demonstrate and to analyse the effectiveness of the rewritten materials for the readers. Also, this paper discusses what postreading activities should be like. There are some suggestions for these activities that have been introduced and tried in actual classes. Considering the fact that most of the reading materials on the text are rewritten, studying the materials through comparison with the originals can be rewarding for teachers.