Oral health in youth is very important because this period influences life for adult remarkably. Therefore, more effective oral health education and recognition of early treatment for oral disease are required sincerely. For more effectual education for high-school students, it is necessary to consider their circumstance like obesity and smoking. This study will analyze the correlation oral health behavior with obesity and subjective oral health concerns. In addition to, the actual condition of smoking for high-school girls and oral health condition will be verified. A survey was progressed for high-school girls in Busan city and BMI(body mass index) was used for classification of weight. The statistical significance was analyzed using SPSS 13.3 for Windows. Results of this study is following. 1. The frequence of daily toothbrushing was significantly different with obesity although difference of oral health knowledge was not significant. The frequency of toothbrushing of overweight students were lesser than the others. This results may be caused by low-level for oral health concerns and by passive life style of fat person. This habit has possibility of causing serious periodontal disease like periodontitis and tooth caries. 2. The correlation of obesity and time of brush change, using for supplement, and recent dental institution was insignificant. However, concerns of oral health were showed significantly according to obesity. Under-weight and standard-weight students were more concerned about oral health than over-weight. This results can be related to frequence of toothbrushing for fat subject. This relevance of two factors was confirmed by logistic regression analysis. 3. Approximately 70% students have smoking experience responded to uncomfortableness of periodontal conditions. On the other hand, non-smoking students felt uncomfortable in 50%. This results indicated that smoking have an effect on oral health condition. Further study which identify periodontal conditions practically has to go on for verification of direct correlation smoking and oral health.