This study aims to explore elementary pre-service teachers’ understanding of science practice in terms of claims in their science journals. Pre-service teachers took a science inquiry course and worked with self-directed inquiry by using Korean science elementary textbook. After inquiry activities, they provided science journals including their test question, data and claims on their inquiry. In order to characterize scientific claims, quality of question, data representation mode, claims were analyzed. The thirty six students’ journals were analyzed. Based on the analyses, frameworks of characterizing scientific claims was suggested. It was followed by discussion regarding the direction of pre-service teacher education of teaching science in elementary school as well.