In order to search for new compounds with new mode of action, high antiulcer activity and lower toxicity, 26(13 pairs of diastereoisomer A and B) 3,4-dihydro-hananensine analogs were synthesized. All compounds were tested in M1 receptor combined assay and gastric ulcer induced by cold-immersion stress in rats. Most compounds showed antiulcer activity, among them IX3A, IX7A, IX8A, IX12A, IX12B and IX13A exhibited more potent antiulcer activity than the control compound cimetidine. Meanwhile, the relationship between their structures and activity was discussed.