The purpose of this study is to explore a science pre-service teacher's naive view of teaching and changes in this view resulting from the practice of teaching and reflection. This study is a case study. The participant is a pre-service teacher who was given practical training for half a year. Data is collected from resource folios, classroom observation and interviews. The results show: (1) the case pre-service teacher has three views of teaching. The first is identifying the role of teachers with a knowledge assigner, and the second is the use of an examination teaching guide, and the third is evaluating teaching using the test scores of students; (2) teaching practice can improve reflection, and reflection can improve professional development. Some suggestions for future research are also discussed in this study.