Abstract: Objective To evaluate the relationship between the microelements in children's hair and their caries in nonferrous metal industrial area in Gansu province.Methods Two hundreds 12-year-old children in nonferrous metal industrial area and the same number of children in control area were randomly sampled.The examination included the condition of dental caries,dental fluorosis and the contents of Zn,Cd,Pb,Fe,Mg and Cu in the children's hair.Results The prevalence and DMF index of children in the nonferrous metal industrial area were markedly higher than those of children in control area and the fluorosis index was on the edge of prevail.The contents of microelement(Zn,Cd,Pb,Fe,Mg,Cu)were higher in the metal industrial area than in control area,especially for Cd and Pb.Conclusion The nonferrous metal microelement pollution caused by the industrial activity may be contributed to the children dental caries in nonferrous metal industrial area.