Objective To evaluate the prevalence of children's dental caries in some nonferrous metal industrial and agricultural areas in Gansu province and to provide a reference for the province's oral health planning.Methods Two hundreds of 5-year-old children and 200 12-year-old in nonferrous metal industrial area and in the neighboring agricultrial area were randomly sampled to examine and complete a questionnairy survey, respectively. The oral examination was included the condition of dental caries and oral hyginene for children of both ages, and dental fluorosis for 12-year-old children.Results The prevalence and DMF index of the 5-year-old children of both the industrial and agricultural areas showed no difference. ②The prevalence, SiC index and DMF index of 12 year-old children in the industrial area showed markedly higher than that of the agricultural area, and the fluorosis index was on the edge of prevalence. ③The oral plaque index of all the children in the industrial area was lower than that of the agricultural area.Conclusion The factors influencing children's dental caries in this nonferrous metal industrial estate may be related with the social status, economical condition and the environment pollution.