Purpose : To determine the effective embolic material and appropriate embolic site by comparing bowel changes after arterial embolization in dogs in which the proximal or distal level of the superior mesenteric artery had been occluded with gelfoam particles or a coil. Material and Methods : Using the coaxial catheter system, superselective arterial embolization was performed at sixteen sites in four dogs. In groups A and B, each site was occluded at the proximal or distal marginal artery, respectively, with gelfoam particles and in groups C and D, at the proximal or distal artery, respectively, with a coi. All dogs were sacrifed one day after the procedure, and gross and microscopic histologic findings were evaluated. Results : In all dogs, the procedure was successful. In group B, significant mucosal destruction, lymphocyte proliferation in submucosa and mucosa, and diffuse swelling in all layers of the intestine were found at all sites. The vessel in the submucosal layer was completely obstructed by red blood cells and gelfoam. At three sites, the intestine showed diffuse ischemic change, and at one other site, focal ischemic change was observed. In group D, exudation with destruction of mucosa and submucosal hemorrhage occurred at one site, but in groups A and C, intestinal layers were found to be normal. Conclusion :Using a coil, superselective arterial embolization was successful, even up to the distal level of the intestinal artery, and the intestine showed no ischemic change. Embolization with gelfoam must be performed carefully at the proximal level, and since it can cause severe intestinal necrosis, must be avoided at the distal level.