This study was intended to explore the process in which teachers college students transform their academic knowledge into teaching practice during concentrated student teaching period in their pre-service training program. Forty senior students majoring in elementary education in National Hualien Teachers College were invited to participate in this study, and qualitative research method was employed. Research findings reveal that(a)student teachers' teaching transformation process during concentrated student teaching process can be divided into four stages, including comprehending and interpreting the textbooks, designing teaching plan, transforming knowledge into teaching action, and reflecting on teaching action; and (b)the extent student teachers transform their academic knowledge into teaching practice depends largely on their instruction beliefs, teaching knowledge, personal experiential knowledge, classroom management effectiveness, and required teaching pace. Several suggestions are recommended for designing teachers college curriculum in general and students' practicum course in particular, aiming for promoting pre-service students' professional growth.