Objective This study was to analyze the causes of the complications of ultrasound -guided percutaneous renal bi-opsy in children . Methods We retrospectively analyzed the complications of ultrasound-guided percutaneous renal biopsy in 236 children along with the age, sex, sample length, times of puncture, and types of disease of the patients .We used the binary Logistic regression model to analyze the influences of various factors on the post -biopsy complications . Results After renal biopsy , 22 (9.3%) of the patients experienced various degrees of but no severe complications .The incidence of complications was significantly correlated with the sample length (P<0.05), but not with the age, sex, sample length, times of puncture, and types of disease of the patients. Conclusion Ultrasound-guided percutaneous renal biopsy is an effective diagnostic method for children , with a high suc-cess rate and a low incidence of complications .And the incidence of complications can be reduced by improving the skills of puncturing and accuracy of ultrasound positioning .