Objective To explore the preventive effect of Weikang granule on gastric ulcer and gastric mucosa damage in rats and its mechanism. Methods Gastric ulcer model was made by stress and pylorus ligature, gastric mucosa damage was made by feeding alcohol to rats. The effect of three different dosage on the rat model were observed. Results In the three treatment groups, there is noticeable resistant effect to the formation of stress and pylorus ligature gastric ulcer of rats. Weikang granule could protect the gastric mucosa from injury caused by alcohol, increase blood flow and content of PGE2. Conclusion It may be the potential mechanism that the prescription can improve the blood circulation of the gastric wall and increase content of PGE2.