Objective To construct a structural equation model for influencing factors of oral health care behaviors in middleaged and elderly diabetic patients based on the Capability

Opportunity

Motivation

Behavior（COM-B） model. Methods A total of 286 middle-aged and elderly diabetic patients who underwent physical examination in a community health service center in Yanji City from July to October 2020 were selected as the study participants by convenience sampling method. Diabetes oral health knowledge

attitude and behavior questionnaire

social support rating scale

and self-rating anxiety scale were used to survey participants. The obtained data were statistically analyzed. Results The scores of oral health knowledge

oral health attitude

and oral health behavior were 18.30±5.43

6.85±2.37

and 11.85±3.75

respectively. The scores of the self-rating anxiety scale and social support rating scale were 48.21±8.94 and 38.81±8.64

respectively. The results of multiple linear stepwise regression showed that the scores of oral health knowledge

oral health attitude

social support rating scale

and self-rating anxiety scale were all the influencing factors of oral health behavior（all P<0.05）

which accounted for 52.4% of the total score variation. The results showed that oral health care attitude played a mediating role between oral health care knowledge and oral health care behavior

with the mediating effect accounting for 24.18% of the total effect; oral health care attitude played a mediating role between social support and oral health care behavior

with the mediating effect accounting for 24.85% of the total effect.Conclusion The oral health care behavior of middle-aged and elderly patients with diabetes lies at a moderate level. Anxiety

social support

oral health care knowledge

and oral health care attitude demonstrate a direct impact on their oral health care behavior. Oral health care attitude plays a mediating role in social support

oral health care knowledge

and oral health care behavior.