Objective To investigate the correlation between dietary patterns and the susceptibility of periodontal diseases. Methods A total of 50 patients newly diagnosed with moderate to severe periodontal diseases and 50 healthy controls were enrolled for the dietary frequency survey. Dietary patterns were established by the factor analysis module of SPSS 19.0 and the correlation between dietary patterns and periodontal diseases was analyzed by multivariate logistic regression model. Results Five dietary patterns were obtained by the factor analysis, i.e. coarse grain pattern, meat pattern, fruit and milk pattern, vegetable and nut pattern, and beverage pattern. After confounding factors were corrected, the coarse grain pattern (OR=0.296, 95%CI 0.102-0.860) and vegetable and nut pattern (OR=0.135, 95%CI 0.049-0.372) negatively correlated with the susceptibility of periodontal diseases, which was statistically significant. Conclusion Dietary patterns that are rich in coarse grains, vegetables, and nuts may be helpful for the prevention of periodontal diseases.