Abstract:Objective: To study the situation of drinking, smoking and oral health between patients with Recurrent Aphthous Ulcer and people in control-group so as to supply the evidence for treatment and self-prevention. Methods: A case-control study was adopted, all patients and pepole in control-group were required to fill in questionaire and accept oral health checking, then differences between two groups were analysed. Results: There was no statistical difference (P >0.05) between two groups in drinking, smoking and oral health. Conclusion: There maybe no direct relation between Recurrent Aphthous Ulcer and drinking, smoking, but it is essential to keep oral healthy when we treat Recurrent Aphthous Ulcer.