The purpose of this study is to analyze the correlation between cause and the element of mouth odor through measurement and identification of mouth odor and is to apply to effective method for elimination of halitosis. Subjects were 150 people who visited Dong Pusan College and lives in Pusan. Cross-sectional survey was used and mouth odor was measured by Oralchroma. Oral examination proceeded with status of tongue plaque distribution and calculus index. Statistical analysis was performed with SPSS version 13.0 for window. Among 150 people, 67.3% subjects thought they had halitosis. 89.3% people felt that their mouth odor were the severest as soon as wake-up. Tongue was serious place for halitosis by 53.3% subjects. Methylmercaptan and dimethyl sulfide showed the highest correlation by 0.549 index score. Moreover, methyl mercaptan was observed the correlation with brushing time in 0.190 index score and with food intake in 0.177(P<0.05). In conclusion, brushing time and food intake were correlated with mouth odor.