The purpose of this study is to explore the motivations of secondary school pre-service teachers in the teaching completion course of teaching profession, focusing on the expectation-value theory. This study was a qualitative study, and data were collected and analyzed through reflective journals with 10 secondary school pre-service teachers enrolled in D University. The results of this study are as follows. The motivations of secondary school pre-service teachers in the teaching completion course of teaching profession were divided into the course of selecting the teaching completion course of teaching profession and conducting the teaching completion course of teaching profession. First, the motivations in the process of selecting the teaching completion course of teaching profession were found by recommendations of the people, relationships with role models, and experiences of teaching. In the context of the expectation-value theory, it was found that the recommendations of the people were related to utility values, the relationships with the role model were related to internal values, attainable values, and the experiences of teaching were related to internal values, attainable values, expected beliefs. Second, the motivations in the process of conducting the teaching completion course of teaching profession were challenges in the process of life, challenges in the process of career design, and challenges in the process of teaching course. In the context of the expectation-value theory, challenges in the process of life were related to attainable values, expected beliefs, challenges in the process of career design were related to utility values, attainable values, expected beliefs, and challenges in the process of teaching course were related to internal values, attainable values, expected beliefs. Based on the results of this study, the implications for the motivation of secondary school pre-service teachers were suggested.