Abstract: OBJECTIVE To research and assess bentonite on the protection of gastric mucosal injury to lay the foundation for the study of its pharmaceutical preparations. METHODS Gastric mucosal injury was induced by aspirin, and ulcer index was observed and calculated. Through gastric histopathology, gastric mucosal MDA content and SOD, GSH-Px activity in serum were measured. pH value of stomach contents was assayed. Gastric barrier mucus was quantitatively determined by means of Alcian blue to stain acidic mucus. RESULTS The pathological examination and biochemical tests presented that when bentonite dose was 50 mg·kg^-1, it had a protective effect on the gastric mucosa of the mice; when the bentonite dose was 200-300 mg·kg^-1, it could significantly improve gastric mucosal damage, inhibit MDA of gastric mucosal, restore the activity of SOD and GSH-Px, and significantly increase the gastric mucus content, but the pH value of stomach contents had no significant effect. CONCLUSION When the dose of bentonite is 200-300 mg·kg^-1, it has an obvious protective effect on gastric mucosal injury model induced by aspirin.