Abstract: Objective:To explore the recurrence mechanism of gastric ulcer and intervention of dendrobium polysaccharides in rats.Methods:The experimental animals were divided into normal group,no recurrence model group,recurrence model group,dendrobium polysaccharide and omeprazole group,dendrobium polysaccharide group and omeprazole group.The recurrence gastric ulcer model was developed by using intraperitoneal injection with interleukin-1.The pathohistological structure of the recurrence gastric ulcer were observed after treatment with dendrobium polysaccharides for 90 days,and the activities of the superoxide dismutase(SOD) and the contents of malondialdehyde(MDA) of gastric mucosa were determined.Results:The activities of SOD of dendrobium polysaccharide and omeprazole group and dendrobium polysaccharide group were significantly improved(P0.01),and the contents of MDA of all groups had no statistical difference(P0.05).The recurrence of gastric ulcer of dendrobium polysaccharide and omeprazole group decresed.Conclusions:The recurrence of the gastric ulcer is related to free radical.Dendrobium polysaccharide and omeprazole can inhibit the recurrence of the gastric ulcer,which mechanism is probably related to anti-oxidation capacity.