Abstract: 　Objectives　To explore the relationship between percent body fat and hypertension in children and adolescents. Method　A cross-sectional study was conducted in 5144 children (2649 boys and 2495 girls) aged 6~13 years. Body height, body weight and blood pressure of all the children were collected, and percent body fat (PBF) was detected by bioelectrical impedance analysis. Either Systolic or diastolic blood pressure above ninety-fifth percentile of that of the same age and gender is considered hypertension. The cut point value of PBF for predicting hypertension was analyzed by ROC curve. Multivariate logistic regression was used to evaluate the effect of PBF on hypertension. Result　The distribution of PBF peaked in ten-yearold boys while it increases with age in girls. The cut-off values of PBF in boys and girls for predicting hypertension were 18% and 18.8% respectively. After controlling for the effects of age, sex, height and body weight, the risk of hypertension increased by 51% (OR=1.51, 95%CI: 1.04~2.07) in boys and 53% (OR=1.53, 95%CI: 1.00~2.34) in girls when the PBF was higher than the cut-off point. PBF was less effective than BMI for predicting hypertension in boys (area under curve for BMI 0.695 vs PBF 0.649, P<0.01) while there was no significant difference between the PBF and BMI in girls (area under curve for BMI 0.650 vs PBF 0.644, P>0.05). Conclusion　The cut-off values of PBF in boys and girls for predicting hypertension were 18% and 18.8% respectively. BMI is still superior to PBF for predicting hypertension in children.