Abstract: Objective To evaluate the oral health conditions of migrant children aged 7-12 in Guangzhou city and that of native children,and to explore its influencing factors,so that to provide information support for the relevant departments to formulate measures to improve their oral health,and for promoting their healthy growth.Methods In April of 2016,random cluster sampling method was applied to select 4 schools in Guangzhou,2 schools for migrant children and the other 2 for native children.In each school,6 classes was chosen,each one from grade 1 to 6.An oral examination was offered to the 1 034 children and a questionnaire was conducted among their parents.Results The caries prevalence rates of the deciduous teeth (67.28%,366/544) and permanent teeth(34.93%,190/544) among the migrant children were higher than those of the native children(34.93%,190/490;2.58%,13/490) (x2 =173.001,174.907,P<0.01).The awareness rate of oral health knowledge and the rate of having a oral health care in the group of native children were higher than tose of migrant children (P<0.01) The differences in caries prevalence rates between groups of different habits of having desserts,and groups of different habits of teeth brushing were of statistical significance(x2 =32.881,22.244,P<0.01).Conclusion The prevalence of dental caries was higher in migrant children in Guangzhou,and the children and their parents had little knowledge of oral health and paid little attention to dental care.Oral health education should be strengthened for primary school students and their parents,especially the migrant children.