Abstract: Objective To observe the claudin-4 expression in inflammatory bowel disease mice models which induced by dextran sulfate sodium (DSS).Methods Fourteen mice were established inflammatory bowel disease models induced by 7-day administration of 2.5％ DSS in water.The other six mice were fed with water only as control group.Pathological changes in colon mucosa were observed on the eighth day.Immunohistochemistry and western blot were used to measure the protein expression of claudin-4 in colon mucosa.Results IBD model was successfully established according to weight and pathological changes.The claudin-4 expression in the model group mice decreased significantly compared with control group and the difference was statistically significant(P ＜0.05).Conclusion Claudin-4 expression level decreased in colon mucosa of IBD mice.The change of the claudin-4 expression may play an important role in IBD development and progression.