This study is to analyze the personality trait and dental fear of high school students. This study is conducted with a total of 603 first grader at high school in DaeGu city from 1st September to 30th October, 2009. In prevention and dental treatment knowledge category, the average score of female are higher than male. The concern of oral health, the experience of oral health education and the number of toothbrush are significantly different in the knowledge category. In dental fear category, the number of dental pain, the visiting is treatment, the recognize of dental state, the number of toothbrush and the change of dental visiting date are significantly different. In the prevention knowledge according to dental fear state, low fear group 7.03 is higher than high fear group. In the dental treatment knowledge according to dental fear state, high fear group 7.15 is higher than low fear group. In personal temperament, there are not significantly relationship between prevention knowledge, dental treatment knowledge and dental fear. These findings are basis to development of education programs which were included prevention and dental treatment knowledge before visiting dental clinics for reducing dental fear.