Objective To determine the prevalence of deciduous tooth caries and its influencing factors among junior kindergarten children of Jiangsu province,and to make recommendation for prevention of dental caries. Methods A closed ended questionnaire according to WHO 1997 methodology was used to collect the data.An epidemiological stratified cluster sampling method was carried out among 25 862 children in junior kindergarten in 13 area of Jiangsu,and the children were examined for the presence of dental caries(at the same time tooth fluoride). Results The overall prevalence of deciduous tooth caries was 41.89% for junior kindergarten of Jiangsu province.Dental caries prevalence of maxillary dentition from high to low was:deciduous teeth,primary lateral incisor,second deciduous molar,first deciduous molar and canine.However,the prevalence of mandibular dentition from high to low was:second deciduous molar,first deciduous molar and mandibular anterior teeth.The prevalence of dental caries in rural was considerably higher than that in urban(P＜0.01),and the prevalence in 4 years old children was extremely high compared with 3 years old children(P＜0.001).However,the prevalence of dental caries had no gender difference (P＞0.05). Conclusions The study concludes that the prevalence of dental caries in junior kindergarten children of Jiangsu province is high.It is necessary to introduce oral health knowledge and increase fluoride application for reducing the caries prevalence of primary dentition and maintaining children of those caries.