Stomach cancer is the most common malignant neoplasm among Korean men and considered as one of the most important malignant disease in many countries. Thus, many studies have been established about factors affecting prognosis of stomach cancer. These include studies of histopathological pattern which were performed by Mulligan and Rember (1954), Lauren (1965), Ming (1977), and Teglbjerg and Vetner(1977). The present study is aimed to evaluate the useful factors to predict the prognosis of patient of stomach cancer in relation to the histopathological patterns. The material consisted of 284 cases which were diagnosed as gastric carcinoma at the Department of Pathology, Yonsei University, College of Medicine from January, 1981 through December, 1982. After the classification of gastric carcinoma by Ming (1977), Willis (1967), and Mulligan and Rember (1954), age and six of the patients, histopathologic patterns, depth of invasion, degree and major component of inflammatory reaction, lymphatic permeation and metastatic incidence to the regional lymph nodes were investigated, and the results obtained were as follows; 1) The overall male to female ratio was 1.4 : 1 and mean age was 51.6 years old. The mean age of patients with EGC was 46.8 years old, while that of patients with invasive cancer was 52.2 years old, indicating about 5 years difference. 2) The classification of 284 cases by Ming's method showed 36.3% of expanding type and 63.7% of infiltrative one. The incidence of metastasis to regional lymph nodes was 58.3% in expanding type and 72.4% in infiltrative one. 3) The classification of 284 cases by Willis' method showed 45.8% of adenocarcinoma and 23.2% and of signet ring cell carcinoma. Adenocarcinoma anaplastic carcinoma had high degree of desmoplasia. Among them, moderately well differentiated adenocarcinoma and anaplastic carcinoma showed markedly lower metastatic rate to regional lymph nodes than others. 4) The classification of 284 cases by Mulligan and Rember's method showed 15.1% of intestinal cell carcinoma, 21.5% of pyloro-cardiac gland cell carcinoma and 61.6% of mucous cell carcinoma. Highly differentiated intestinal cell and pylorocardiac gland cell carcinomas and desmoplastic mucous cell carcinoma had high degree of desmoplasia. Among them, highly differentiated intestinal cell carcinoma and desmoplastic mucous cell carcinoma showed markedly low metastatic rate to regional lymph nodes. 5) Adenocarcinoma with good differentiation showed higher mean age and male predominancy in comparison to carcinoma with poor differentiation. 6) The degree of inflammatory reaction did not show significant difference in relation to the patterns of gastric carcinoma and the rate of regional node metastasis. However, according to the cell types involved in inflammatory reaction, plasma cell-predominant inflammatory reaction showed low metastatic rate to regional lymph nodes. 7) The more the degree of desmoplasia was observed, the less the rate of metastasis to regional nodes was noted and the difference was statistically significant. 8) The rate of metastasis to regional nodes showed marked difference by the depth of cancer invasion; confined to mucosa, 0% : to submucosa, 15.4%; to muscular layer, 66.7%; and to serosa and perigastric area, 76.5%. In summary, the results of this study indicated several factors suggesting good prognosis, such as; (1) expanding growth pattern, (2) good differentiation, (3) high degree of desmoplasia as stromal reaction, (4) plasma cell-predominant infiltration, and (5) lesser deep invasion. These factors were better evaluated by Mulligan and Rember's classification.