This paper reports a narrative study on the teacher identity development of an EFL pre-service teacher during the teaching practicum program in Indonesia. Guided by the teacher's personal interpretive framework of Kelchtermans' (Kelchtermans, 1993) theory, this study examined written reflective narratives as a tool to determine the professional identity development of an English pre-service teacher. Therefore, data were obtained through reflective narratives written by the participant during the teaching practicum program. They were analyzed using thematic analysis. The findings showed that teaching practicum plays an important role in professional development. Reflecting on the narratives, it not only captures past experiences but also demonstrates professional self-understanding where the teacher’s profession and professional context are tightly intertwined with one’s personal histories, so, the teacher can integrate her personal and professional skills in positioning themselves. Therefore, the reflective narratives made it possible for the pre-service teacher to identify her teacher identity development through self-positioning as a teacher which helps her to develop her sense of belonging to understand the teaching profession. Moreover, practicing teaching in the real-classroom setting, interacting with the students, interacting with an experienced mentor teacher, and conducting peer reviews of each other's teaching performance throughout the entire teaching practicum program are indicated as the factors that she encountered and considered to influence her in developing herself as a teacher over her narrated past as well as during practicum. Finally, the findings provide implications for teacher education in supporting pre-service English language teachers to construct and develop their self-concept as teachers during completing study in a teacher education program to prepare them as newly qualified teachers with well-equipped professional identities.