It is important to evaluate the effectiveness of teaching materials for science classes in order to improve them and develop classes. In this paper. I examined some materials used in geological field study as examples of science teaching materials, describing them and the process of evaluating them. Then I discussed the present state and problems of evaluating materials for geological field study, based on previous studies. In addition, I showed that in order to evaluate teaching materials for geological field study we need a learning place, a learning text. and a teaching plan. Moreover, I pointed out two directions in evaluating materials of geological field study: evaluating materials synthetically and evaluating the process of students' scientific thinking through geological field study.