This study was performed to evaluate the potentiality of Reynoutria elliptica Migo., being used as a folk remedy and a herb medicine for urethritis, cystitis, etc., on growth inhibition of Helicobacter pylori which is known as the ulcerogenic pathogen. The minimum inhibitory concentration (MIC) value of methanol extract from Reynoutria elliptica Migo, was determined to be 120 ppm for H. pylori and urease activity derived from H. pylori was inhibited over 80% by the extract at 2 mg/mL in urea broth. Among various solvent fraction of the methanol extract, the hexane fraction showed a significant inhibitory effect on the growth of H. pylori reducing both its growth and urease activity. Scanning and transmission electron micrographs of H. pylori treated with the methanol extract at 2 mg/mL for 3 hr showed that the cell walls and membranes were disrupted so that the cytoplasmic components were leaked from the body. These results suggest that Reynoutria elliptica Migo. possesses a therapeutic potential on the gastric disease caused by H. pylori.