Objectives : The purpose of this study was to examine the relationship of stress symptoms, oral habits and temporomanbibular joint symptom among 20-30 ages adults. And it``s also meant to investigate the direct and indirect influence of these factors by using a path model to determine their causal relationship. Methods : The subjects in this study were 287 selected 20-30 ages adults, on whom a survey was conducted from June 15 to July 10, 2014. The data were analyzed using SPSS 18.0(SPSS 18.0 K for window, SPSS Inc USA) and IBM SPSS Amos 18.0(SPSS Inc, Chicago, IL, USA). Results : There were significant differences in oral habits, TMJ symptoms and stress according to gender. There were significant differences in oral habits, TMJ symptoms, physical and psycho-emotional symptoms according to Systemic disease. And stress, physical, psycho emotional symptoms, oral habits and TMJ symptoms were correlated to one another. Stress exerted a direct influence on physical, psycho-emotional symptoms, and psycho-emotional symptoms had a direct impact on physical symptoms, oral habits and TMJ symptoms. Physical symptoms exercised a direct influence on oral habits and TMJ symptoms, and oral habits affected TMJ symptoms in a direct way. physical, psycho-emotional symptoms and oral habits served as parameters that produced partial mediation effects, and the two factors had an indirect impact on TMJ symptoms. Conclusions : It``s found that stress exerted direct and indirect influence on oral parafunction and TMJ symptoms. Like other diseases, oral habits and TMJ symptom that stem from stress is likely to lead to chronic diseases if the two are not noticed at the right time. Therefore individual people should try to get rid of stress in a manner to be appropriate for their own characteristics in order to maintain their oral health.