Objective To evaluate the value of the level of peripheral blood elements in children with recurrent respiratory tract infection(RRTI),and study the relationship between peripheral blood elements and RRTI in children. Methods The registered data of elements in peripheral blood examination was collected in Chengde Central Hospital pediatric clinic from November 2015 to March 2016.6 months to 4 years old children were randomly selected as the research object.132 cases of children suffering from RRTI were study group,and the healthy children of the same period were set up as the normal control group.Children in each group were divided into three age groups,under 1 year of age group,1~2 years old group and >2 years older group.In this study,Beijing Bohui BH5100S atomic absorption spectrometer were employed to determine the children's peripheral blood.Data were analyzed by SPSS 19.0 statistical software. Results 1)The levels of blood zinc had significant differences (P<0.01) between RRTI group and the control in children among different ages.There were also statistical significance (P<0.05) in the level of blood calcium between two groups in children under 1 year old.Moreover,there were statistical significances (P<0.05) in the levels of blood calcium and iron between two groups in children of >2 age,and the level of iron reached significant level too (P<0.01).2)According to the correlation analysis of five trace elements,the result indicated that calcium,zinc and iron were positively correlated. Conclusion The RRTI is related to the lack of zinc,and there is a certain relationship with the deficiency of calcium and iron,and there might be synergistic effects in the metabolism process among them.