Abstract: Objective To investigate the effect of zinc deficiency on the development of children's intelligence.Methods All the children were divided into three groups according to their symptoms:control group,symptomatic zinc deficiency group,asymptomatic zinc deficiency group.Both serum zinc and IQ level of each group was measured before and after zinc treatment.Correlation analysis was made between serum zinc and intelligence.IQ of zinc deficiency groups was compared before and after zinc treatment.Results The seurm zinc level of asymptomatic zinc deficiency group was higher slightly than that of symptomatic group(P<0.01);Both were lower significantly than that of control group(P<0.01);there was positive correlation between serum zinc and intelligene(r=0.325,P<0.01,n=100);IQ asymptomatic zinc deficiency group was higher slightly than that of symptomatic zinc deficiency group(P>0.05);IQ of zinc deficiency groups was lower significantly than that of control group(P<0.01).After treatment,both serum zinc level and intelligence of zinc deficiency groups were improved significantly(P<0.01),and there was no statistic difference between zinc deficiency groups and normal group(P>0.05).Conclusion Zinc was an important factor that affected the development of children's intelligence.Zinc deficiency could delay intelligence development.In some degree,this effect could be reverted by zinc treatment.To improve children's intelligence development,zinc treatment should be applied immediately after zinc deficiency was diagnosed.