AIM: To compare two types of classification of intestinal metaplasia (IM) of the stomach and to explore their relationship to gastric carcinoma.METHODS: Forty-seven cases of gastric IM were classified into type Ⅰ, type Ⅱ or type Ⅲ according to mucin histochemical staining and compared with a novel classification in which the specimens were classified into simple IM (SIM) or atypical IM according to polymorphism in terms of atypical changes of the metaplastic epithelium. Forty-seven IM and thirty-seven gastric carcinoma samples were stained for p53, c-erbB-2 and Ki67 proteins by Envision immunohistochemical technique.RESULTS: There were no significant differences in the expression of p53 and c-erbB-2 among type Ⅰ, type Ⅱ, type Ⅲ IM and gastric carcinomas. The positive expression rate of Ki67 was significantly higher in gastric carcinomas than in type Ⅰ IM while no significant Ki67 expression differences were observed among type Ⅱ,type Ⅲ IM and gastric carcinomas. The expression of p53, c-erbB-2 and Ki67 proteins in 20 SIM, 27 Atypical IM and 37 gastric carcinomas showed significant differences between SIM and gastric carcinomas while no significant differences were observed between Atypical IM and gastric carcinomas.CONCLUSION: Atypical IM may better reveal the precancerous nature of IM and could be a helpful indicator in the clinical follow up of patients.