A clinical review was carried out in 64 cases of gastric cancer of the 3rd decade male patients who were diagnosed at the Department of Surgery, Capital Armed Forces General Hospital between Jan. 1980 and Dec. 1989. The results were as follows; 1) The incidence of gastric cancer in 3rd decade male patients was 23.8% among the all gastric cancers. 2) The incidence of gastric cancer in 21-25 of age was 60.9%< and 26-30 of age was 39.1% among the 3rd decade gastric cancers. 3) The patients with blood type A were 39.1#9p and blood types 0, B, AB were 29.1%p, 25.0%, 6.2% in order. 4) Chief complaints in order of frequency were as follows; epigastric pain (75.0%), indigetion (35.9%) and weight. loss (31.2%). On physical exeminations, epigastric tenderness (73.4%), epigastric palpable mass (32.8%), and anemia (29.7%) were common. 5) Most patients were admitted to hospital after 6 months of illness. (59.4%) 6) The preoperative diagnostic rate was 82.0% by UGIS, 90.1% by gastroscopy and 93.8% by endoscopic biopsy. 7) The most common site of tumor was pylorus and antrum (65.6%). 8) The most popular size distribution of primary tumor was between 4 and 8 cm in diameter(42.2%). 9) In Borrmanns classification, common types were type III (46.9%) and type II (29.7%), and early gastric cancer was 3 cases (4.7%). 10) In pathologic findings, the most common type was adenocarcinoma (76.6%). 11)Regional lymph node metastasis was seen in 77.4% of resected cases, and distant metastasis was in pancreas, liver and mesocolon in order. 12) Curative gastric resection was performed in 30 cases of the 62 cases (48.4%) and resectability