Abstract: Teaching practice and the related educational theory are important factors in teacher development, and their relationship has been a major concern. Some discussions on the relationship focus on the problem of pendulum vibration swinging to theory preference or practice preference, which has long been a resistance to teacher development, hence the practical doctrines and the theoretic doctrines in teacher development. According to the practical doctrines, teacher development mainly relies on the accumulation of individual experiences and learning from others. Only in this way can a teacher make proper decision to ensure the smooth process of educational activity; thus teacher development is a bottom–up way and practice preference. On the other hand, according to the theoretic doctrines, teacher development is a reflective action originating from a living subsistence. Under the constraints of his individual knowledge organization, daily focuses and thinking habits, it's so hard for a teacher to create a universal development theory that he has to turn to educational theorist's guidance to overcome the shortcomings of his experiences. In the long-standing conflict between "practical experience line" and "theoretic guidance line", there appears in teacher development the phenomenon of pendulum swing. At times when the theoretic guidance line is prevailing, teaching practice tends to be underestimated by the educational theorists, causing the lack of subjectivity and agency in teacher development. Then, the values of teachers' practical experience are reexamined and refocused, and the theoretic guidance line could be reconstructed and surpassed. And the line of education theory preference gradually swings to the line practical experience preference. Studies show that the pendulum swing between practical experience and educational theory has caused the blind theoretical privilege or theoretical inferiority and submissive to the practice among educational theorists. This could lead to teachers' disorientation or resistance to the educational theory and turn to his experiences. So, it's necessary to reexamine the relationship between educational theory and practical experience, which will help improve teacher development.In this article, the author argues that nowadays if the educational theorists expect educational theories to play an effective role in teacher's practice, they must engage themselves in teachers' practical life, and generate new educational theories on the base of respect and understanding of teachers' practice. On the other hand, if teachers want to seek a better professional development, they must intervene in theorist's theoretical life, and by learning educational theories and the reconstruction of practical theory, they can improve their theoretical practice.