OBJECTIVE: To evaluated the gastroprotective effects of standardized aqueous extract of Ziziphus jujuba(Z. jujuba) stem bark against acidified ethanol-induced gastric ulcers as well as anti helicobacter pylori activity of the plant extract in rats.METHODS: Five groups of rats were orally pre-treated with normal saline(0.9%) as ulcer group, 150 mg/kg of ranitidine as positive control group, 100, 200 and 400 mg of standardized extract solution as the experimental groups. Two hours later, acidified ethanol solution was given by gavages in order to induce of gastric ulcer. The antibacterial effect of extract against clinical strains of Helicobacter pylori(H. pylori) was evaluated through disc diffusion test.RESULTS: The ulcer group exhibited significantly severe mucosal injury as compared with ranitidine or extract group which shows significant protective action against gastric mucosal injury. The extract showed no effect on H. pylori.CONCLUSION: The present study indicates that Z.jujuba stem bark extract had a potential antiulcer activity which might be due to its protective activity, providing a direct, protective effect on the gastric mucosa. Our study showed that anti-H. pylori activity was not among gastroprotective mechanism of Z. jujuba. Further pre-clinical and clinical investigations for evaluating natural active agents and efficacy of this plant are recommended.