【Objective】 To observe the contents change of zinc,ferrum,calcium,magnesium,copper,lead,manganese and selenium in blood of children with asthma,and explore significance in pathogenesis. 【Method】 1 986 children with asthma were selected as observing group and 856 normal children were randomly chosen as control.Serum zinc,ferrum,calcium,magnesium,copper,lead,manganese and selenium were detected and compared between the two groups. 【Results】 Serum zinc,ferrum and calcium in the asthma group were obviously lower than those in the control group,and serum lead in the asthma group was obviously higher than that in the control group (P＜0.05).There were no significance differences between the two groups of serum copper,magnesium,selenium,manganese (P all＞0.05).Asthma in an acute attack,blood content of zinc,calcium were lower than those in remission(P＜0.05). 【Conclusion】 Microelement zinc,ferrum and calcium deficiency and increased lead plays an important role in the occurrence and development process of children asthma,which may be an important reason for immune function reduction and immune regulation disturbance.More attention should be paid to the relationship between microelement in blood and the prevention and the cure of excessive lead when we treat the children with asthma.