Abstract： Objective To explore the effect of seawater immersion on intestinal barrier following open abdominal injury in dogs. Methods Twenty adult mongrel dogs were randomly divided into the control group (n = 10) and the seawater immersion group (n = 10). The control group was immediately observed under microscope following abdominal injury, while the seawater immersion group was instantly put into the manually prepared seawater after abdominal injury. Blood samples were taken before injury (0 hour) and at 4, 8, 12,and 24 hours after injury for detection of endotoxin, glutamine, D-lactate, diamine oxidase (DAO). Samples of 24-hour urine were collected for measurement of lactulose / mannitol (L/M) ratio. The intestinal tissue samples were obtained 24 hours after seawater immersion for pathological examination. Results Compared with the control group, the seawater immersion group showed clear signs of intestinal barrier dysfunction. Serum Dlactate, and DAO activity tended to increase progressively, and significant differences could be noted 8 hours after immersion ( P ＜ 0. 05 ). However, glutamine was detected to be declining, and significant differences could be observed at hour 12 following seawater immersion, when compared with that of the control group (P ＜0. 01 ). Plasma endotoxin level of the seawater immersion group increased significantly 12 hours after seawater immersion when compared with that of the control group (P ＜ 0. 05 ). The 24-hour urine L/M ratio also showed significant differences ( P ＜ 0. 05 ). For the seawater immersion group, portal vein and mesenteric lymph node hacterial culture showed that there was a substantial colony, and significant differences could be seen, when a comparison was made between the two groups (P ＜0.01 ). Pathological examination indicated that the seawater immersion group had significant lesion in intestinal mueosa, as evidenced by a significant reduction of mucosal thickness and villous height ( P ＜ 0. 05 ), when a comparison was made between the 2 groups. Conclusions Seawater immersion could induce lesion to the intestinal barrier function following open abdominal injury in dogs.