Most kidney tumors are malignant, except for a few renal vascular smooth muscle lipomas and isolated fibroids. If a tumor is found in the kidney, how should it be treated in general? Firstly, the nature of renal tumor is initially determined based on imaging, especially CT and in a few cases, MRI is needed to identify angiosmooth muscle lipoma and renal cancer. If the imaging is highly suggestive of angiosmooth muscle lipoma, nephrectomy with kidney preservation is generally feasible unless the tumor has destroyed the kidney so severely that the kidney is no longer functional, or there is bleeding from tumor rupture, and total nephrectomy is feasible. If the imaging examination is highly suggestive of malignant renal cell carcinoma, it should be considered according to the stage, size, location, relationship with renal blood vessels, whether there are lymph node metastasis, lung metastasis, etc. If the malignant kidney tumor is confined to the kidney, according to the doctor’s experience, kidney preservation surgery can be performed. The past era of total nephrectomy for kidney cancer has passed.