We know that a person cannot live without kidneys or with severely underfunctioning kidneys unless replacement therapy (e.g., hemodialysis or peritoneal dialysis) or a kidney transplant is taken. Radical nephrectomy has been the standard treatment for kidney cancer treatment. However, in the case of kidney cancer when there is only one kidney (i.e., isolated kidney), or when there is kidney cancer in both kidneys, or when there are two kidneys, one of which has a tumor, and the other has atrophied and is not functioning due to disease or other reasons (i.e., functionally isolated kidney), if radical nephrectomy (i.e., the standard of care for kidney cancer) were to be taken in these cases, the patient would be left with no kidneys or would suffer from renal insufficiency. Insufficiency. We know that without kidneys or with severe renal insufficiency, a person cannot live unless he/she receives replacement therapy (e.g. hemodialysis or peritoneal dialysis) or a kidney transplant. Both dialysis and transplantation are very expensive, not to mention their side effects or impact on quality of life. Therefore, whenever possible, these kidney cancer patients should undergo kidney-preserving surgery, which removes the tumor and preserves the functional normal kidney tissue. Kidney preservation surgery has a long history, and in recent years, laparoscopy has been applied to perform kidney preservation surgery in a minimally invasive way. After multi-center clinical observation, it was found that patients got very good results after renal preservation surgery, and the actual results were comparable to those of radical nephrectomy if compared according to the tumor stage, which provided strong evidence for performing renal preservation surgery in other renal cancer patients in the future. In medicine, kidney-sparing surgery for these kidney cancer patients is called absolute indication. Encouraged by the above results, urologists began to apply renal conservation surgery to those renal cancer patients who suffer from diseases that have potential threat to renal function (e.g. hypertension, diabetes mellitus, systemic lupus erythematosus, hyperuricemia, chronic nephritis or pyelonephritis, renal vasculopathy, etc.), even though the patient’s total renal function is normal at the time of surgery, the above mentioned diseases may cause renal function impairment and development of renal function damage in the near future after removing one kidney. cause the occurrence of renal function damage and develop renal insufficiency or uremia. After long-term observation of a large number of cases, good tumor control results have been achieved in these patients. Kidney preservation surgery in these renal cancer patients is called the relative indications for kidney preservation surgery. With the above two types of kidney cancer patients who have achieved good results in renal-conserving surgery, is it appropriate to perform renal-conserving surgery if the kidney function is completely normal, there is no disease that affects the kidney function, and the tumor is below 4-125px? After observing a large number of clinical cases, the effect of kidney-preserving surgery is almost the same as that of radical nephrectomy. Many previous worries (such as tumor recurrence and metastasis) about kidney preserving surgery for this kind of kidney cancer patients have been dispelled in front of the fact. This is the third type of indication of renal surgery for kidney cancer, i.e., selective indication. Compared with radical nephrectomy, renal insufficiency and proteinuria symptoms are significantly reduced after kidney preserving surgery. Moreover, nowadays laparoscopic surgery for kidney cancer has the advantages of short hospitalization time, fast recovery, less bleeding, small incision and good aesthetics, which significantly improves the quality of life of patients.