Objective To observe the complication after embolizing the bilateral internal il iac arteries and the median sacral artery of dogs by different combinations and embolization levels with gelfoam particle, and to provide a reference for safety appl ication of gelfoam in cl inic. Methods Sixteen common grade adult healthy dogs (weighing 10-13 kg, 14 males and 2females) were randomly divided into 5 groups. Under the monitoring of digital subtraction angiography (DSA), the embolization was performed with gelfoam particle (diameter, 50-150 μm) in bilateral internal il iac arteries and the main branch of the median sacral artery (group A, n=3), in bilateral internal il iac arteries and the first branch of the median sacral artery (group B, n=3), in the main branch of bilateral internal il iac arteries (group C, n=3), in the unilateral internal il iac artery and the main branch of the median sacral artery (group D, n=4), and in the main branch of unilateral internal il iac artery (group E, n=3). Under the DSA, the anatomic relationships of the abdominal aorta, bilateral external il iac arteries, bilateral internal il iac arteries, and median sacral artery were observed before embol ization. The survival dogs were observed and the specimens of bladder, rectum, sciatic nerve, and gluteal muscles were harvested for the general and histological observations at 3 days after embolization. Results In dogs, there was no common il iac artery; bilateral external il iac arteries originated from the abdominal aorta and the starting of the median sacral artery had variation. Seven dogs (3 in group A, 3 in group C, and 1 in group D) died within 2 days after embolization, and the others survived to the end of the experiment. In the dead dogs of groups A, C, and D, the darkening and necrosis of the rectum were observed; the bladder presented lamellar obfuscation and focal hemorrhage and edema; and the median urinary volume in bladder was 270.6 mL. In survival dogs, no obvious change was observed in the rectum; the bladder only manifested l ight edema; and the median urinary volume in bladder was 137.0, 220.5, and 28.0 mL, respectively in groups B, D, and E.The rectum and bladder of dead dogs in groups A, C, and D manifested the disrupted cells, generous inflammatory cells infiltration, and desquamation of epithel ial cells; the rectum and bladder of survival dogs in groups B, D, and E manifested l ight inflammatory cells infiltration and edema; the embol ized artery mainly focused on the arterioles whose diameter was 100-200 μm. The sciatic nerve and gluteal muscles of each group had no obvious change except for l ight edema. Conclusion When the internal il iac artery and median sacral artery are embol ized with gelfoam particle with a diameter of 50-150 μm, to ensure the safeness of pelvic organs, the embol ized artery can not exceed the first branch when the 3 arteries are embol ized at the same time, or reserve at least unilateral internal il iac artery when embol ized to the trunk , or it will result in pelvic organ necrosis and perforation.