fPatients with mental disability who are classified as dental severely disabled, have poor oral health status and many difficulties in taking health services. The purpose of this study was to investigate factors of influencing in visiting oral health care services. After receiving approval from institutional review board in Seoul National University, 39 participants were recruited and the oral health examination and questionnaire were taken. Data were analyzed using one-way ANOVA, independent t-test, hierarchical linear regression for predicting influence of each participants’ characteristics on oral examination time and care time. In regression model, the higher the disability grade and the lower the degree of cooperation, the more oral examination time increased. However possibility of communication was not significantly influenced. Also, the higher the disability grade and the lower the degree of cooperation, the more oral care time increased. However possibility of communication was not significantly influenced. These results are expected to provide objective data for introduction and establishment of visiting dental care.