Objective: To explore the ultrasonographic features and ultrasonographic diagnostic value of clear cell sarcoma of kidney (CCSK) in children. Methods: Analysis ultrasound imaging data and ultrasound''s diagnostic value of 18 patients with pathologically confirmed CCSK retrospectively. Results: 18cases were all single, 9 cases showed moderate echoes, 6 cases showed moderately strong, 3 cases showed moderately low echoes; 7 cases were solid, 13 of which were accompanied with echogenic areas of varying sizes(6 cases were cystic mixed lesions, 7 cases were substantial lesions containing a little liquid component). 14 cases showed residual kidney，6 cases showed separated renal pelvis；4 cases crossed the midline；7 cases were rich in blood flow, 2 cases were rather rich in blood flow, the rest did not see exactly blood flow; 2 cases showed vascular bulging sign. 11 cases gone CT examination, and only 1 case suggested that CCSK could not be excluded. Conclusion: The images of CCSK and nephroblastoma are similarity. Ultrasound and CT are both difficult to identify CCSK. Ultrasound is safer and radiation-free. It can be used as the first choice of imaging method to identify and follow-up CCSK.