Abstract: ObjectiveTo know the prevalence of essential hypertension(EHT)among students of middle school in the area with high prevalence rate of EHT and to study the relationship between serum iron(SI)and EHT.MethodsIn Zhangwu county,Liaoning province.1 164 students were selected using randomized sampling method.The questionnaire was used for Some related factors of EHT.Results122 EHT of students were diagnosed and the prevalence rate was 7.44%.The average level of DBP in female was significantly higherthan that in male(t=5.807,P<0.05).The level of SI in EHT group was higher than that in control group,but there was no statistical difference(t=1.348,P<0.05).In male,there were significant differences of SI in hypertension,high SBP and DBP group compared to control group respectively(t=3.630,P<0.05;t=1.965,P<0.05).The OR value of high level of SI was 1.733(OR=1.733,95% CI=1.081～2.777).Thehigh level of SI in male had a influence on the SBP and DBP(OR=4.455,95% CI=1.871～10.609;OR=3.383,95% CI=1.637-6.994).There was apositive correlation between SBP and SI level(r=0.053,P<0.031).ConclusionThe results showed that SI probably is a risk factor for EHT in middle school students especially in male.