Objective:To investigate the relationship between levels of serum thyroid stimulating hormone(TSH)and blood pressure in the school-age children and adolescents. Methods:A cross-sectional survey on 880 subjects aged 7~18 in Bengbu,Anhui province was carried out with a questionnaire,blood pressure,height,and body weight measurement on the basis of random cluster sampling method. Blood samples were taken in fasting state to test TSH. FT3 and FT4 were further examined if TSH was abnormal. The relationship between different levels of serum TSH and systolic and diastolic blood pressure(SBP and DBP)was analyzed. Results:①Serum TSH and SBP,DBP were positively correlated. After adjusting for age,sex,and body mass index(BMI),the positive correlation between TSH and blood pressure was still remained and was more significant in male(correlation coefficient r=0.115 5,0.130 2,P=0.007,0.002). ②SBP and DBP in subclinical hypothyroidism group were higher than those in normal subjects,increased by 2.6 mmHg,2.2 mmHg,respectively. Conclusion:SBP and DBP were increased with the increment of TSH in normal subjects and the participants with subclinical thyroid disease. Among the school-age children and adolescents,blood pressure was higher in subclinical hypothyroidism subjects than that in normal. This study provides evidence for screening thyroid function in hypertensive children and adolescents and treatment for subclinical hypothyroidism.