目的 分析我国学龄前儿童龋齿患病情况与其口腔健康行为的相关性，为有针对性地开展儿童龋齿防控工作提供依据。方法 数据来源于2019—2021年开展的科技基础资源调查专项“中国0～18岁儿童营养与健康系统调查与应用”项目，对来自全国7个区域14个省(自治区、直辖市)的9 841名学龄前儿童的人口学特征、是否龋齿、饮食和刷牙习惯等口腔卫生健康行为数据进行分析。结果 学龄前儿童龋齿患病率为33.70%,3～、4～、5～6岁儿童龋齿患病率分别为25.60%、34.61%和40.42%，呈逐渐增长趋势(χ²_趋势=12.58,P <0.001)。城市儿童龋齿患病率高于农村儿童(37.77%与29.44%)，且差异有统计学意义(P <0.001)。经常被允许吃任何喜欢的食物的儿童患龋率(36.87%)高于很少或偶尔有此行为的儿童(33.05%)，三餐后经常刷牙或漱口的儿童患龋率(32.17%)较低。结论 我国学龄前儿童龋齿患病率相对较高，儿童龋齿与被允许吃任何喜欢的食物、三餐后刷牙或漱口等口腔健康行为相关。儿童和家长应提高口腔健康的知识和态度，形成正确的口腔健康行为习惯，促进儿童口腔健康。

Objective To analysis the association between dental caries prevalence and oral health behavior of preschool children,in order to provide evidence for preventing dental caries.Methods The research data came from the national special program for science&technology basic resources investigation of China,named“National Nutrition and Health Systematic Survey for 0～18 years Old Children in China”which surveyed from 2019 to 2021.And the data of 9 841 preschool children’s demographic characteristics,children’s dental caries and their oral health behavior were analyzed,the children were from 14 provinces (autonomous region,municipality directly under the central government) of 7 areas.Results The prevalence of dental caries in preschool children was33.70%.The prevalence of dental caries in children aged 3-,4-,and 5-6 years old were 25.6%,34.61%and 40.42%,respectively,showing a gradual increase trend (χ²_trend=12.58,P<0.001).The prevalence of dental caries in urban children was higher than that in rural children (37.77%vs.29.44%) and there was difference statistically significant (P<0.001).Children who were often allowed to eat any food they liked had higher dental caries (36.87%)than those who were rarely or occasionally allowed to do so (33.05%),and children who brushed or rinsed their teeth after three meals had lower prevalence of dental caries (32.17%).Conclusions The prevalence of dental caries in preschool children is high.Dental caries was associated with oral health behavior,such as being allowed to eat any food they liked and brushing or rinsed their teeth after three meals.Parents and children should improve their knowledge and awareness of oral health,develop good oral health habits,and promote children's oral health.