Abstract: Objective: to study the causes of misdiagnosis of renal cell carcinoma. Methods:38 misdiagnosis cases of renal cell carcinoma were retrospectively analyzed between 1987.12-2007.11，causes of misdiagnosis were analyzed by combining clinical expression and features of imaging.Results: 7 cases of renal cell carcinoma were misdiagnosed by angiomyolipoma;14 cases of angiomyolipoma were misdiagnosed by renal cell carcinoma， Other misdiagnosed cases， 8 were xanthogranulomatous pyelonephritis ， 4 were multilocular cystic nephroma，2 were leiomyoma of kidney ，2 were renal abscess，one case were renal fibrolipoma .Conclusion:Understanding the clinical expression and imaging specificity， puncture biopsy guied by B-ultrasonography before operation and frozen pathological section during operation for cases of atypical imagine expression could avoid misdiagnosis and resection of kidney.