1.1. Aims: The aim of this study was to analyze the association between mental health and dental caries in graduate students in China. 1.2. Methods: Three structured psychological scales, includ ing the Symptom Checklist 90, Perceived Social Support Scale, and General Well-Being Schedule were administered to evaluate mental health. Dental caries consists of three parts, oral question naires, caries susceptibility tests and caries examinations. Oral questionnaires assessing oral health, oral hygiene, and oral habits were regarded as potential confounding factors. Cariostat caries susceptibility test was used to evaluate caries susceptibility.