The purpose of this study is to criticize Korean language lesson of good class inquiry contest and to show significance of it. Prospective teachers participating in the competition share the teaching and learning skills they have learned at the school and on the field, and compete as teachers. However, a good class that breaks the frame of standardized or formalized class is possible when practicing class based on the literacy of the curriculum and reconstruction of the textbook. Particularly, because it taught the same subjects and unit, I could not help but pay attention to reconstruction of the textbooks of preliminary teachers. I tried to explore what is a good class, how it is possible, and what its educational significance is. The more open and active the teacher according to the change of the age, the more the curriculum is analyzed critically and the class is practiced. Therefore, the preliminary teachers should critically evaluate the class and improve creatively to expand the class capacity. As a result of the criticism of the class, I presented what the practicality and limitations of your class are and suggested some concrete action plans for the future class. In order to grow as a teaching expert in the future, the preliminary teachers focused on finding out what efforts should be made and how to do them. These studies will accumulate and ultimately hope to improve the quality of education and improve the educational environment and class culture.