Pancreatic pseudocyst is encapsulated collections of exudate, blood, and secretions that result from pancreatic necrosis or rupture of ducts and acini, and frequently results invarious life threating comlications. The barium study of the upper G.I. tract is the most valuable method in diagnosis of the pancreatic pseudocyst. Total 30 cases of surgically proved pancreatic pseudocyst were analysed. The result were as follows; 1. 56.6% was male, and peak incidence was in the 5th decade. 2. Etiologic factors were blunt abdominal trauma(30%) pancreatitis(23%), and unknown(47%). 3. The most important radiologic finding was stomach displacement (100%), and the others were colon displacement (69%), mass seen in simple abdomen(67%), left kidney displacement(46%), duodenal deformity(40%), elevation of diaphragm(37%), pleural effusion (27%), and pancreatic calcification(7%). 4. The most frequent site of the pseudocyst in U.G.I. series was between the greater curvature of the antrum of the stomach and transverse colon(40%). The other sits were near the incisura angularis of the lesser curvature(12%), greater curvature of the antrum (12%), and greater curvature of the body of stomach(4%). 5. The location of the pseudocyt was mainly in the body and tail of the pancreas(90%), only 3 cses (10%) was in the head.