This study was performed to determine effect of oral health behavior and influencing factor of oral health behavior, and variables of theory of planned behavior before and after oral health education in hospitalized–alcoholic patients. The survey was administered to 32 male patients and was conducted on the structured self-administered questionnaires and oral health education. To analysis data, the covariance structure analysis was conducted. With the analysis of covariance structure, oral health behavior was influenced with explanatory powers of before (60.3%) and after (96.6%) by oral health education by variables of theory of planned behavior. It was indicated more strong relationship by oral health education. The effect was strongly increased according to oral health education. Therefore the effective oral health education program requires improving of the oral health for subjects with poor oral environment and low management capacity.