Abstract: Objective To research risk factors of dental fluorosis in 12 years-old children and to provide evidence for dental fluorosis control.Methods A 1:2 gender,living area matching case-control study was conducted with a questionnaire survey.Results Fathers' education,mothers' education,getting oral health knowledge from TV or radio,drinking milk,using fluorosis toothpaste,and brushing teeth more than one time a day were significant influencing factors for dental fluorosis with the odds ratios(OR) of 6.75,7.86,0.67,0.41,0.64,and 1.20,respectively.Condition logistic analysis revealed that drinking milk was negatively correlated with dental fluorosis significantly(OR=0.30).Conclusion The nutrition of children should be improved.Oral healthy knowledge should be enhanced among children's parents in Guangzhou.