Objective To explore the effect of mothers' intervention on oral health behavior of children in Nanning city,to provide data support for the develop oral health education program of the 2.5~4.5 years old children's mother and constructing oral health promotion community network of maternal and child in Nanning city community. Methods Totally 834 children aged 2.5~4.5 years old from 6 nurseries and kindergartens in two communities were selected by random sampling and mothers were surveyed by a questionnaire,intervention factors of oral health behavior of children were analysed by Logistic regression analysis. Results The children brushed their teeth two times a day and more was 38.5%,had oral treatment was 34.0%,used fluoride toothpaste was 20.9%,had a sweet tooth before bed was 74.1%.There was correlation between oral health behavior of children and mother's education level,the mother helped the child to brush their teeth and checked the effect of brushing teeth,the mother's knowledge of regular oral examination and fluoride toothpaste to the teeth. Conclusions The oral health behaviors of children are not perfect in Nanning.The influence factors of mothers' culture should be focus on improving their oral health knowledge targeted,strengthen the behavior of the mother to interfere with the children's oral hygiene and take corresponding preventive measures.