As yet, only effective treatment in gastric cancer is early diagnosis and early curative gastric resection,Howeaver, almost all cases of gastric cancer, when diagnosed, are advanced cancer and large proportion of them areinoperable because of distant metastasis and peritoneal dissemination. Some half of explorated gastric cancers areunresectable because of extension into adjacent organs or regional lymphnodes. Authors analysed U.G.I. series in 30 cases of unresectable gastric cancer and 30 cases of resected advanced gastric cancer, explorated at SeoulNational University Hospital. Results are as follows; 1. In unresectable cases, findings of gastric fixation isobserved in 775 and normal in 23%, in contrast to 13% and 87%, respectively, in resectable cases. 2. Retrogastricspace is widened in 97% of unresectable gastric cancer and is normal in only 3%, in contrast to 33% and 67%,respectively, inresectable cases. 3. In unresectable cases, C-loop widening is observed much more frequently thanin resectable cases. 4. In unresectable cases, gastric cancer is more frequent in the body portion, and morefrequently infiltrative in type and more extensive in extent in comparison with that of resectable cases. 5. Itmay be said conclusively, findings of gastaric fixation and retrogastric mass are indicative findings ofunresectability in gastric cancer.