Abstract: Objective:To determine the Clinical characteristics and risk factors of essential hypertension in children and adolescents.Methods: PATIENTS:43 children and adolescents（admitted from February 1994 to July 2007） with EH,8 to 18 years old.CONTROL GROUP: 23 healthy children and adolescents（admitted from February 1994 to July 2007）,8 to 18 years old.STUDY DESIGN: controlled study.Evaluation of anthropometrical data,age,gender,height,weight,family history towards hypertension was made.In two groups blood routine,urine routine,routine biochemical tests,electrocardiogram and abdominal ultrasonography examination were measured.The data were analyzed using CHISS.Results: There was a statistically significant relationship between family history of hypertension and EH in children and adolescents.Among the EH group,BMI,the rate of male and ECG abnormality,serum uric acid and sodium levels were higher than those in healthy control group（P＜0.05）.Conclusion: EH in children and adolescents correlates with BMI,gender,family history of hypertension,uric acid,serum sodium,and ECG abnormality.