This study aims to find an improvement of textbook adoption through teachers' perceptions on textbook adoption. The focuses of arguments established in this study are as follows：First, Korean teachers do not think that a textbook authorization is good way. Their satisfaction degree about that policy and the process of textbook adoption are not high. Nevertheless, they think that the textbook authorization is an appropriate way for the present. Therefore, it is necessary to improve the textbook authorization by revising whole one. Second, it suggests that we should expand a period of textbook adoption and provide information about textbook. Most teachers consider that textbook adoption is hard work because the number of textbook is too much and adoption period is too short. Therefore, we should expand the period of adoption, cut down the number, and provide information about textbook through public hearing. Third, it is important that we should give shape to textbook adoption criteria. The criteria that teachers emphasis is how suitable for students' level. It is needed to provide criteria that can consider condition of each school. By doing so, we should adopt textbook by clear criteria for good textbook.