The Purpose of this study was to examine the difference amon elementary, middle, and high school in creative thinking ability and creative personality. Creative thinking ability was measured by TTCT(Torrance, 1974). The creative personality was measured by CPI(Hah, 2001). Approximately 749 participants were selected in Seoul area in Korea. Developmental trends by grades were analyzed and the results of this study were as follows. First, the result showed that main effect of school was revealed significantly in creative thinking ability(fluency, originality, elaboration, Abstractness of title). Second, the result showed that main effect of school was revealed significantly in creative personalities(curiosity, self-confidence, imagination, patience, humor, independence, challenge, openness). Rather, this result supported the increment view in creative thinking ability from elementary school to high school students. However, the scores of creative personality decreased from the elementary school students steadily in this study. As students get into higher grades, they are more likely to compare and evaluate with their peers. Also, they are under more peer pressure to confirm.