Practical knowledge is the knowledge the teacher reconstructs by synthesizing and reconstructing the theoretical knowledge according to the one's belief and the point of value considering the real situation, which becomes the basis of the teaching. The study of the practical knowledge has been approached in two aspects. One is to reveal and understand the teacher's practical knowledge which is absorbed in their real teaching situation. The other is to provide the opportunity to the teachers to realize and revaluate the practical knowledge they have in order to support their growth. This study manifests that it is necessary to help the pre-teachers to construct the practical knowledge which can applied properly various teaching situations and also to provide the opportunity for the present teachers to reflect and develop their practical knowledge.