The purpose of the present article is to analyze the communicativeness of English Oral Communication B textbooks currently used in senior high schools in Japan. As part of the present Course of Study, the Ministry of Education introduced a new kind of course, Oral Communication A, B, and C and the actual instructions began in the classroom in 1994. In line with the recent communicative trend, there has been a growing expectation of dramatic changes in the teaching of oral English. There has been a great deal of discussion on the effective techniques for using textbooks and supplementary materials; however, relatively less attention has been focused on Oral Communication textbooks. They have been used without much critical analysis. Very little research has been carried out to day on how communicative those textbooks actually are. The present analyzed the dyad or sometimes triad interactions found in the Oral Communication B textbook and classified them into three categories: formulaic, information-exchange, and pragmatic. Based on the findings, some suggestions are made concerning possible improvements in the design and use of senior high school textbooks.