Abstract: Objective To investigate the prevalence of caries in native children and nonnative children located in Changning District of Shanghai. Methods A survey of caries was performed in 645 native children and 614 nonnative children in Shanghai according to the Criteria for National Oral Epidemiologic Survey. Results Caries prevalence rate in deciduous teeth of native children was 26.98%,dmft was 0.87 and dmfs was 1.51. Caries prevalence rate in deciduous teeth of nonnative children was 47.07%,dmft was 1.76 and dmfs was 3.08.There was significant difference between two groups(P<0.01). Conclusions Prevalence of deciduous tooth caries in 3yearold nonnative children in Changning District of Shanghai is obviously higher than that in native children in this district.More attention should be addressed to caries prevention and treatment in nonnative children.