The purpose of this research is to find the degree of the performance of teachers' instructional activities through their self-evaluation and investigate the information needed to improve their instructional activities. The major findings of this study are as follows ; First, elementary school teachers are aware of the fact that they have a low performance level compared with middle school teachers in the field of knowledge of a course. This suggests that teachers' heavy burden on instructions and the students' situation should be considered and also the subject teacher system should be fully, not partly, carried out. Secondly, The newly-appointed teachers' performance ability of their instructional activities are low. It results from some problems of the program for training teachers. In relation to these problems with the curriculum, some reformative measures for the teacher education program are needed. The measures include strengthening the connection between universities and elementary/ secondary schools, properly operating the cooperative schools, and utilizing qualified teachers in charge of trainee-teachers.