Introduction: H. pylori is a bacterial pathogen associated with gastric cancer. Changes in the glycosylation patterns on cells and specific glycotransferases are reportedly related to cell proliferation, differentiation, tissue adhesion, and carcinogenesis. There is no report that described changes of glycosylation in H. pylori infection and after eradication. Thus, in the present study, we used a lectin microarray system to analyze relationship of the gastric mucosal glycosylation and H. pylori infection. Methods: We selected 10 H. pylori uninfected patients, 10 H. pylori infected patients and 6 H. pylori eradicated gastric cancer patients who underwent gastric mucosal biopsy by endoscopy in our institute. In H. pylori infected patients, we performed biopsy again one year after H. pylori eradication. We collected the gastric mucosal cells by using LCM(Laser Capture Microdissection) and extracted protein. Results: In the gasric antrum, the expression of 3 lectins, SNA(Sambucus nigra), TJA-I(Trichosanthes japonica agglutinin I) and ACG(Agrocybe cylindracea galectin) were increased significantly in H. pylori infected mucosa compared with that in H. pyloriuninfected. In contrast, the expression of 2 lectins, Jacalin and MPA(Maclura pomifera agglutinin) were decreased(Fig.1). Interestingly, after H. pylori eradication, the decreased expression of these lectins were recovered(Fig.1). In the gastric body, the expression of 3 lectins, SNA, SSA(Sambucus sieboldiana) and TJA-I were increased. After H. pylori eradication, the increased expression of these lectins were recovered. However, in H. pylorieradicated gastric cancer patients, the expression of two lectins; SSA and TJA-I were similar to those of H. pylori infected patients(Fig.2). Conclusion: This study shows that the expression of 6 lectins were changed significantly by H. pylori infection. The expression of Jacalin and MPA were decreased by H. pylori infection, and was increased by eradication. Furthermore, the expression of SSA and TJA-I were increased in H. pylori infection and gastric cancer which found after H. pylori eradication group. eradication It is suggested that these lectins are associated with H. pylori infection.