Objectives : This study conducted to investigate oral care abilities in diabetic patients to find a good dental method which may efficiently control diabetes. Methods : The diabetic group consisted of 40 patients with type 2 diabetics, while the non-diabetes were 34 persons with no signs of diabetics, who had visited a Public Health Center and dental clinic of a general hospital in Gwangju city from Dec. 2008 to Sep. 2009. Periodontal disease, gingivitis, dental caries, tongue plaque and halitosis between diabetic group and non-diabetic group were examined and at the same time a questionnaire survey was conducted. The data were analyzed with chi-square, t-test, pearson correlation coefficients using the SPSS WIN 15.0 program. Results : The mean values of both the community periodontal index and the gingival index of diabetic group were 2.18 and 1.75, respectively, and those were higher than those (1.79 and 1.50) of non-diabetic group with no statistical significance. The mean saliva secretion of non-diabetics was 16.74 mL, which was higher than 13.90 mL of diabetic patients(p<0.05). The oral care ability(mean 3.10) acquired from plague index in diabetic group was worse than in non-diabetic(mean 2.33). Conclusions : The high blood sugar concentration in diabetic patients causes low saliva secretion and high saliva viscosity, with the results halitosis and periodontal disease take place. This study suggested that good oral care ability of diabetic patients was very helpful to prevent periodontal disease and halitosis. In addition to this, it may reduce complications of diabetic patients.