This research explains the role of the small group discussion by examining the situation that reading is promoted. The first, the function of the small group discussion which stimulates reading is supported by two bases. That is to contribute private interpretation, and to have the responsibility that it answers to the friend's remark. The second, a small group discussion has the function which make a learner realize the amusement which interpretation is exchanged for. The third, a small group discussion has the function to promote a learner's inquiry.