Objective        To investigate the incidence of root caries in Hui elderly people of Linxia Hui Autonomous Prefecture

Gansu Province.        Methods       Root caries in 436 Hui elderly people aged 65-74 years and their clinical examination were investigated with questionnaire by random sampling according to the third national oral health survey standards and methods.       Results       The incidence of root caries in Hui elderly people of Linxia Hui Autonomous Prefecture was 28.90%

with mean number of root caries of 0.42. No significant difference was found in the incidence of root caries between urban and rural areas and between male and female (P0.05). The filling rate of root caries was only 0.68%. The root caries index (RCI) value was 2.85% and 2.76%

respectively

in the distal and mesial surfaces. The RCI value was higher in maxillary teeth than in corresponding mandibular teeth. Root caries involving one root surface was detected in 88.7% of Hui elderly people. Logistic regression analysis showed that frequency of teeth brushing and sugar food intake was closely related with the occurrence of root caries in Hui elderly people of Linxia Hui Autonomous Prefecture （OR:0.492

95%CI:0.317 to 0.764

P=0.002；OR:1.654

95%CI:1.033 to 2.648

P=0.036）.       Conclusion       The incidence of root caries in Hui elderly people of Linxia Hui Autonomous Prefecture is low due to their good oral health and life habits. However

root caries is rarely treated

thus needing instructions on their oral health and taking more preventive measures against their oral diseases.