Abstract: Objective To study the application of ultrasound-guided biopsy in diagnosis of retroperitoneal diseases and summarize the ultrasonographic features of retroperitoneal tumors. Methods Forty-seven patients with retroperitoneal diseases who underwent ultrasound-guided biopsy in our department from September 2009 to April 2013 were included in this study.They were followed up for months,during which they were finally diagnosed with retroperitoneal diseases according to their pathological examination,imaging data and laboratory findings.Their complications were observed. Results The success biopsy rate was 100%.Of the 47 patients,44 were diagnosed with retroperitoneal diseases by histopathology with a qualitative diagnostic rate of 93.6%（44/47） and qualitative biopsy diagnosis rate of 100%（44/44）.The sensitivity,specificity and accuracy of biopsy were 97.4%,100% and 97.9%,respectively.No complication occurred in the patients after biopsy.Some retroperitoneal tumors showed characteristic ultrasound images. Conclusion The accuracy of ultrasound-guided biopsy is high in diagnosis of retroperitoneal diseases with few complications and can thus be used in their clinical diagnosis and treatment.