Objective To investigate the clinical, imaging and pathological manifestations of retroperitoneal leiomyosarcoma, and to make a diagnosis and differential diagnosis in order to improve the understanding of the disease. Methods The clinical data of 11 patients with retroperitoneal leiomyosarcoma with surgical pathology were analyzed retrospectively, And make an analysis with relative literature. Results Seven cases were located in the right front of the inferior vena cava, and 3 cases were located in the front of the abdominal aorta and 1 cases in the pelvic cavity. The 8 cases were irregular in shape, and the 3 cases were elliptic. 6 cases with invasion of inferior vena cava, 8 cases of peripheral organs, 3 cases of liver metastasis. In the 10 cases, the density was not uniform and the necrosis cyst was seen in the center. In the dynamic enhancement scanning, the essential components showed progressive and continuous enhancement, and the cystic necrosis region was not enhanced. 2 cases of calcified lesions were seen. Pathological examination demonstrated spindleshaped tumor cells with significant heteromorphism. Conclusion The retroperitoneal leiomyosarcoma is rare and its clinical manifestation is atypical, the CT performance has certain characteristic, but the final diagnosis still needs pathology.