There are many types of renal tumors with complex tissue origin, which can be divided into two categories: benign and malignant. Some benign tumors that are small in size and do not cause clinical symptoms, such as renal adenoma, smooth muscle tumor, lipoma, and lymphoma are often accidental findings in nephrectomy specimens or autopsy and have little clinical significance. Renal malignancies are generally considered to be divided into the following four types: ① malignant tumors of adult renal parenchyma; ② nephroblastoma and other embryonal tumors of the kidney; ③ epithelial cell carcinoma of the renal pelvis; ④ malignant tumors of interstitial, peritoneal and peripheral tissue origin. Among adult malignant tumors, renal tumors account for about 2-6%, most of which are renal carcinomas, and fewer are pelvic carcinomas. Among pediatric malignancies, nephroblastoma accounts for more than 20%, and is the most common abdominal tumor in pediatric patients. Among the composition of renal tumors, renal cancer accounts for more than 80% in western countries, pelvic cancer accounts for about 10%, and the others are nephroblastoma and so on. In China, the proportion of renal pelvis cancer is about 20%, which is higher than that in western countries, the reason is not clear. In recent years, the proportion of renal pelvic cancer is decreasing, which may be related to the imaging progress to find more incidental renal cancers. Renal tumors in China occupy the second place among urological and male genital tumors, after bladder tumors.