Ultrasonography is a very useul diagnostic modality for the evaluation of clinically suspicious abdominalmasses in infants and children, especially in assessing their existence, size,location, origin and internalconsistency. Authors analyzed and present ultrasonographic findings of 92 pathologically and/or clinically provenpediatric abdominal masses that were studied and treated in Chonnam University Hospital during recent 4 years. Theresults were as follows: 1. The most common originating site was kidney(26 cases: 28.3%), followed bygastrointestinal tract (21 cases: 22.8%), genital organ(17 cases: 18.5%), non-renal retroperitoneum (13cases:18.5%), hepatobilary tract (12 cases:13.0%), and anterior abdominal wall (3 cases: 3.3%) in ordre offrequency. 2. The most common mass was hydonephrosis(18 cases: 19.6%). Neuroblastoma(7 cases:7.6%),hepatoblastoma, ovarian teratoma, periappendiceal abscess and abdominal tuberculosis(6 cases: 6.5%, respectively),Wilms tumor(5 cases: 5.4%) were next in order of frequency. 3. The sex distribution is rather similar, that is ,male 42(45.7%) and female 50(54.3%), but characteristically choledochal cyst(2 cases) and genital mass(17 cases)were found only in females. Considering age distribution, 78 cases(84.8%) were found within the range of one to 15years of age. The rest, 14 cases(15.2%), were under the age of one year. 4. With ultrasonography, the diagnosis ofhydronephrosis could be made easily in every case and we could evaluate its severity and level of obstruction withhigh accuracy. 5. All Wilms tumor were large, round or oval, sharply marginated and relatively homogenous solidmasses. 6. All neuroblastomas were irregular shaped, poorly defined, heterogeneous solid masses. Tumorcalcification and extension across the midline were noted in 6 cases(85.7%) and 5 cases(71.4%), respectively. 7.All periappendiceal abscesses had irregular thickened wall and posterior acoustic enhancement: 4 cases (66.7%)among them were mixed echo pattern and 2 cases(33.3%) ehco free. 8. Among the 6 abdominal tuberculoses, 2 wereseen as irregularly defined solid masses, 1 as conglomeration of multiple hypoechoic nodulles and 3 as mixedpatterns. 9. All hepatoblastomas were seen to be poorly marginated solid masses with more echogenicity thanadjacent normal hepatic echo in 5 cases except one. 10. Among the 6 ovarian teraomas, 4 cases were cystic and 2cases solid. Acoutic shadowing was seen in 3 cases. 11. Choledochal cyst (2 cases), hydrops of gallbladder(1cases) and cyst of pancreas head(1 cases) had similar ultrasonic appearance as a large elliptical systic mass,but, it was important in differential diagnosis to ascertain the existence of gallblader and the connectionbetween the cyst and bile duct.