Objective To discuss the clinical presentation of retroperitoneal tumor and its MR and CT appearance.Methods The study conducted by selecting 58 cases of patients with retroperitoneal tumor of one hospital of Xianning district of Hubei from January 2011 to September 2014.Imaging and clinical feature of retroperitoneal tumor were analyzed.Methods of MR and CT

based on results of pathological examination

were compared in terms of sensibility

specificity and accuracy.Results Patients with retroperitoneal tumor aged over 49 years had the highest incidence（81.0%）

among which 23 cases were benign lesions（39.7%）;35cases were malignant lesions（60.3%）.The lesion types focused on liposarcoma

schwannoma and paraganglioma

occupying 25.9%

24.1% and 20.7% respectively.Of the 34 cases correct diagnosis of malignant lesion and of 23 cases correct diagnosis of benign lesion by employing MR

1of 23 was false benign lesion and 0of 34 was false malignant lesion

manifesting 98.3% accuracy（57/58）

100.0% specificity（23/23）and 97.1%sensibility（34/35）.Of the 32 cases correct diagnosis of malignant lesion and of 23 cases correct diagnosis of benign lesion by employing CT

3of 23 were false benign lesion and 0of 32 was false malignant lesion

showing 94.8% accuracy（55/58）

100.0%specificity（23/23）and 91.4%sensibility（32/35）.Conclusion Combination use of MR and CT can improve early diagnosis efficiency and diagnosis accuracy in patients with retroperitoneal tumor

which is worthy to be popularized.