28 patients with chronic antral gastritis, 22 patients with duodenal peptic ulcer and 16 healthy persons underwent morphological and functional examination of fundus glands before and after eradication of H. pylori in. According to the findings, patients with H. Pylori invasion had malfunction of fundus glands enhancing aggressive properties of gastric content due to increasing in number of main and parietal cells, decreasing in number of supplementary glandular cells and thus inappropriate protective function of gastric mucosa. H. pylori eradication has brought to adequate number of cells in fundus glands and restoration their normal relations.