Objective To investigate the prevalence and influence factors of caries in grade one children in Fengxian district of Shanghai, and to provide support for the prevention of caries in children.

Methods By cluster random sampling method, 1 141 grade one children in 22 primary schools in Fengxian district of Shanghai were clinically examined by dentists, and their oral health questionnaires were distributed by school doctors.

Results The caries rate of grade one children in Fengxian district was 60.74%, while the filling rate was 18.27%, and the mean dmft score was 2.25±2.72. General or poor oral health status of children was the risk factor of caries (P < 0.01). With no dental visits children as reference, the last dental visit time within 12 months was a risk factor for caries in grade one children (P < 0.05). With frequent toothache in the past 12 months, absence of toothache was a protective factor for caries (P < 0.05).

Conclusions The caries status of grade one children in Fengxian district is not optimistic. Oral health education in families, schools, and society should be strengthened. Meanwhile, parents should pay more attention to children's oral health and help their children establish good oral health behaviors and take their children for oral check-up regularly, so as to improve children's oral health and prevent the occurrence of dental caries in children.