Objective: To compare anti-gastric ulcer action of sea buckthorn pulp oil(SBPO) with sea buckthorn seed oil(SBSO) and to explore its mechanism. Methods : The anti-gastric ulcer actions of SBPO and SBSO were observed and compared on the gastric ulcer induced by water immersion stress, reserpine, pylorus ligation and acetic acid. The effects on gastric secretion in rats were studied with pylorus ligation. The effects on gastric emptying were observed by methyl orange remaining rate in stomach of mouse. The analgesic effect was tested by the hot-plate method and writhing method. Results : SBPO and SBSO markedly inhibited gastric ulcer induced by water immersion stress, reserpine and pylorus ligation and promoted the healing of the gastric ulcer induced by acetic acid. SBPO and SBSO significantly inhibited the secretion of gastric acid and pepsin and promoted the secretion of gastric mucous. SBPO and SBSO delayed gastric emptying in normal mouse. SBPO and SBSO significantly decreased the number of twisting body in mice. Conclusion : Both SBPO and SBSO could have anti-gastric ulcer effect with similar potency. The mechanism of anti-gastric ulcer might be their effect of inhibition of the secrection of gastric juice, promotion of the secrection of gastric mucous, inhibition of activity of gastric smooth muscle and analgetic effect.