It is generally accepted that radical nephrectomy and partial nephrectomy are equivalent in terms of tumor control for renal cell carcinoma smaller than 4 cm and limited renal carcinoma, and that non-tumor-specific mortality is significantly higher in the radical nephrectomy group in the long term. The Cleveland Clinic Medical Center has conducted a study of 485 tumors. A long-term follow-up study of 485 patients with renal cancer who had partial nephrectomy before 1996 at Cleveland Clinic showed that 98% of patients had normal residual renal function on the affected side, with a 5-year specific survival rate of 93% and a recurrence rate of 9% (44//485), of which 3.2% were local recurrences. The 5-year survival rate was 88.2%, the 10-year survival rate was 73%, and the long-term follow-up rate of normal kidney function was 93% in 107 patients with partially resected kidney cancer. At present, the indications for preserving renal unit surgery can be summarized as follows: 1. Indications: renal cancer occurs in patients with anatomical or functional isolated kidney, and radical nephrectomy will lead to renal insufficiency or uremia, such as congenital isolated kidney, contralateral renal insufficiency or non-functional person, double kidney cancer, etc. 2. Relative indications: certain benign diseases exist in the contralateral kidney of renal cancer, such as renal stone, chronic nephritis or diseases that can lead to renal function deterioration. 3. 3.Optional indications: patients with normal contralateral kidney function, clinical stage T1a (tumor ≤4cm), tumor located in the periphery of kidney, single asymptomatic kidney cancer, clinical stage T1b (maximum tumor diameter 4-7cm).