Abstract: OBJECTIVE To study the effect of Amomi Fructus water extraction on intestinal mucosal barrier function in rats induced by 5-FU. METHODS SPF SD rats were divided into normal control group, model group, positive drug group and water extract of Amomi Fructus(48, 96, 192 mg·kg^-1) groups, 8 rats in each group. The normal control group was intraperitoneally injected with saline for 5 d, and the other groups were intraperitoneally injected with 35 mg·kg^-1 5-FU for 5 d. From the beginning of the experiment, the normal control group were given saline, and the other groups were given the corresponding therapeutic drugs for fasting and gavage for 12 d. Diarrhea occurrence, weight and food intakes were recorded daily throughout the study in rats. Blood samples and the small intestinal were collected after killing of rats for evaluation of histopathology, the content of cytokines (IL-6, ROS, NF-kB, MPO and TNF-α) and LPS were detected by ELISA. The intestinal tight junction protein ZO-1, occludin and caspase-3 were measured by flow cytometry. RESULTS Water extract of Amomi Fructus significantly improved rats body weight, food intakes diarrhea and significantly reversed the hisopathological changes in intestinal mucositis induced by 5-FU and reduced the inflammatory parameters (IL-6, ROS) in blood sample. It could also significantly effectively reduce the content of NF-κB, TNF-α, MPO in small intestinal tissue and the effect was similar to the positive drug. Meanwhile, it showed that water extract of Amomi Fructus could increase the expression of occludin and decrease the expression of caspase-3, inhibit the translocation of LPS, protect the integrity of intestinal barrier function. CONCLUSION It is suggested that the water extract of Amomi Fructus may play an important protective role in intestinal mucositis and gut barrier injury in rats challenged by 5-FU, 96 mg·kg^-1 shows best effect, which may contribute to inhibit ROS generated, decrease pro-inflammatory cytokines secrete, inhibit NF-κB signaling, caspase-3 signaling and suppress the MPO activity, further decrease apoptosis, inhibit the translocation of LPS and protect the integrity of mucosal.