Abstract: Acute mesenteric ischemia (AMI) is a life threatening disease, with high mortality rate and is easily misdiag nosed. Rapid and acute detection of the AMI and its primary diseases by multi slice computed tomography (MSCT) and computed tomography angiography (CTA) is of great significance. The clinical data of 31 patients with AMI who were admitted to the Xidian Group Hospital from January 2005 to June 2013 were retrospectively analyzed. Stenosis or occlusion of the mesenteric blood vessels, diminished or absent enhancement of the bowel wall are the direct signs of CT, thickening of the bowel wall is the most typical indirect sign of CT. Dilatation or collapse of the bowel lumen and swelling of the mesenterium are the common CT signs. Pneumatosis intestinalis and gas in the portomesenteric vein are reliable CT signs of the Intestinal Infarction. Artery and venous embolism, atherosclerosis, vasculitis, aortitis, strangulated intestinal obstruction and superior mesenteric artery dissection are the possible causes of AMI.