In order to find out how writing is taught in junior and senior high school, the current Course of Study for high school, a total of 105 text books and their manuals for teachers were analyzed. The present paper reports a part of this study, with a focus on teaching of punctuation. Results show that most of basic punctuation marks are taught from very early in junior high school, when English sentences are presented for the first time. Teaching of punctuation, however, does not seem to be done from there on until students take reading and writing courses in senior high school. These results based on textbook analyses were partially supported by a small-scale questionnaire study, in which 38 Keio university students were asked about how they learned writing in high school. Also, it was found that a further study on other learning materials used in senior high school is necessary to get a full picture on how punctuation is taught in high school in Japan.