The purpose of the present study is to describe a music teacher's experience with teaching portfolio to enhance her own reflection and teaching. The target of the case study is an elementary music teacher in Nantou County, Taiwan. The observation period lasted one semester. Data collected include interview transcripts, lesson plans, teacher journals, student journals, field notes, checklist assessment sheets, worksheets, teaching material developed by the teacher, photos and videotapes. The participant teacher reported that the use of teaching portfolio enhanced her reflective thinking and improved her teaching effectiveness. A discussion of such response is included in the end of the paper.