Objectives : This study investigated the correlation between dry mouth and comprehensive diagnosis of Qi xu and Qi yu in patients with halitosis. Methods : We surveyed 124 halitosis patients by reviewing the questionnaires from the Halitosis Clinic in the Hospital of Oriental Medicine, Kyunghee University from January 2004 to March 2006. The halitosis questionnaires contained self-awareness of halitosis, self-assessed severity of halitosis, dry mouth and taste abnormality. Among comprehensive diagnosis of Qui Xue Shui, Qi xu and Qi yu parts were investigated by questionnaire and physical examination, and each Qi xu and Qi yu part scores were summed. Winkel tongue coating index was estimated by investigator, the level of volatile sulfur compounds were measured by halimeter, and salivary function was assessed by salivary scan test. All patients were divided into two groups based on salivary scan test (salivary function normal and decreased). Results : Qi xu score of halitosis patients with decreased salivary function was higher than normal halitosis patients. There was highly significant correlation between Qi yu score and dry mouth, and another significant correlation between self-assessed halitosis severity and dry mouth was noted. Conclusions : The results of this study suggest that Qi yu condition influences dry mouth in halitosis patients, and halitosis is affected by dry mouth. Therefore. we assume that treating Qi yu condition can be a potentially effective way of treating dry mouth and halitosis.