Undifferentiated embryonal sarcoma (UES) is an uncommon malignant hepatic tumor that occurs in older children and young adults. Six cases of UES were reviewed to determine their characterisfic findings on sonography (US) (n=5), computed tomography (CT) (n=6), and angiography (n=2) US demonstrated a single large, echogenic mass with some anechoic spaces in each case. CT revealed a well demarcated hypodense mass with hyperdinse septa of variable shape and thickness. Four cases showed enhancing peripheral rim and some solid portions at the periphery or adjacent to the septa. Follow-up CT scan in one case who had not been treated showed enhancing solid portion changed to hypodense areas. Angiography showed hypovasculsr of avaxcular mass. Familiarity with these radiological findings of UES of liver will be helpful in differential diagnosis of primary hepatic tumors of childhood.