281 cases of neonatal and infantile intestinal obstruction confirmed by clinical and surgical procedure from1975 till 1979 were reveiwed radiologically. The result was as follows; 1. Intussusception was the most commoncause of intestinal obstruction under one year of age (173/281 : 61.56%), and other causes of descending orderwere infantile hypertrophic pyloric stenosis(20 :7.11%), congenital megacolon (19 :6.76%), anorectalmalformation(17: 6.05%), meconium plug syndrome (17:6.05%), hernia(12:4.27%), band adhesion(8:2.85%), rotationanomaly(5:1.78%), small bowel atresia(3:1.07%), Meckel's diverticulum (3:1.07%), duodenal atresia(2:0,71%),meconium ileus(1:0.36%) and annular pancreas (1:0.36%). Congenital type of intestinal obstruction (we classifiedintussusception acquired and others congenital ) occupied 38.44%. 2. The ratio of male to female was 3:1,congenital type 4.69 :1 and acquired 2.39:1. 3. Vomiting, bloody stool, fever and abdominal distention were themost 4 symptoms. 4. The frequency of typical mechanical ileus pattern on plain abdomen films was 226 cases(80.43%) paralytic ileus or normal finding was 52 cases (18.51%) and pneumoperitoneum with ileus sign was 3 cases(1.06%). 5. Barium meal or enema was performed in 228 cases and narrowing or obstructed site was found in 213cases of them(93.42%); intussusception 100%(173/173), infantile hypertrophic pyloric stenosis93.33%(14/15) andcongenital megacolon 82.35%(14/17). 6. Only 10 cases had associated diseases such as Mongolism, thoracic kyphosisand scoliosis, microcolon, prematurity, ileocolic fistula, undescended testicle and hydrocele. 7. Meconium plugsyndrome, duodenal atresia, small bowel atresia, mecondium ileus and annular pancreas were developed early afterbirth with average onset age of 3.6 days.