Objective　To study clinical anatomy and application of ilioinguinal approach through retroperitoneal space in the management of massive hemorrhage from pelvic fractures. 　Methods　The retroperitoneal space was exposed by both left and right ilioinguinal approaches on 37cadaver specimens, and parameters as follows were measured: the route and relationship of vessels and ureters; the anterior translation of inferior mesenteric artery, ureters, and testicular or ovarian artery and vena. The ilioinguinal approach was clinically performed for 12 cases of massive hemorrhage from pelvic fractures, 10 males and 2 females.  Results    The abdominal aorta, inferior vena cava, and common iliac artery and vena, in the retroperitoneal space, were firmly attached to the pelvic wall, and separated from the peritoneum with extraperitoneal fat; inferior mesenteric artery, testicular or ovarian artery and vena and parietal peritoneum are connected with each other by dense connective tissue, and could be lifted with parietal peritoneum with ease; the upper end of ureter has connection with parietal peritoneum, with the lower end loosely connected to it. The inferior mesenteric artery could  be anteriorly translated by 19.3 mm on the plane of L4, while the testicular or ovarian artery and vena could be anteriorly translated by 26.4 mm(right) and 28.0 mm(left), and the ureters 37.0 mm(left) and 41.0 mm(right). The ilioinguinal approach was clinically performed for 12 cases of massive hemorrhage from pelvic fractures, through the procedure of which the abdominal aorta compression was conducted to temporarily control the massive hemorrhage, with the shock rescued and corrected, the damaged vessels ligated and repaired, and the fractures fixed. There were 11cases of success and 1 case of death; on the whole, no vascular, nerve and vascular intimal injuries occurred.    Conclusions    The ilioinguinal approach through retroperitoneal space can completely expose major vessels in pelvis;  temporary abdominal aorta compression is a rapid and an effective way to control massive hemorrhage and correct shock, increasing the success rate in treatment of massive hemorrhage from pelvic fractures. This operative approach proves effective in rescuing patients with pelvic fractures complicated with large blood vessel injury.