A 44-years old female was adimitted to Guro Hospital because of epigastric pain. Endoscopy showed several small sized and slightly depressed erythematous 1esions on the greater curvature of upper antrum. Endoscopic biopsy was done. The microscopic examination of the biopsy specimens showed mucosa associated lymphoid tissue(MALT) lymphoma lesions at gastric submucosa with the invasion of B lymphocytes forming lymphoepithelium and many foci of Helicobacter pylori(H. pylori) infection. Therefore, the treatment to H. pylori with the combined prescription with omeprazole, amoxycillin, and metronidazole was done for 2 weeks. The follow-up endoscopic biopsy was done at 1 month after the end of antimicrobial therapy. The follow-up biopsy specimens showed only mild gastritis lesions without the invasion of B lymphocytes and H.pylories. Hence, we present a case of MALT gastric lymphoma associated with H. pylori infection and successfully treated with anti-H. ori therapy.