This study was carried out to investigate the immunohistochemical expression of bcl-2 and p53 protein in the intestinal type and the diffuse type of gastric adenocarcinoma by Lauren's classification. A total of 100 cases, including 50 cases of the intestinal type and 50 cases of the diffuse type from paraffin embedded gastrectomy specimens, were immunohistochemically stained for bcl-2 and p53 protein. Bcl-2 protein was expressed in 38% (19/50) of intestinal type and 30% (15/50) of diffuse type. The incidence of bcl-2 protein expression was higher in the intestinal type than in the diffuse type, but no significant correlation was present (p>0.05). p53 protein was expressed in 68% (34/50) of the intestinal type and 60% (30/50) of the diffuse type. The incidence of p53 protein expression was higher in the intestinal type than in the diffuse type, but no significant correlation was present (p>0.05). And an expression of bcl-2 and p53 protein did not correlate with depth of invasion, lymph node meatastasis and TNM stage, respectively (p>0.05). These results suggest that bcl-2 and p53 gene alteration appear to play a more important role in the carcinogenesis of the intestinal type than the diffuse type. However, there is no significant difference between the intestinaPU: The Korean Society of Pathologistsl type and the diffuse type in bcl-2 and p53 protein expression.