Renal pathological examination, known as renal puncture biopsy, is performed by removing a small piece or pieces of tissue from the kidney using a renal puncture needle and examining it through pathology to make a correct diagnosis of kidney disease. Kidney biopsy is one of the most important tests for diagnosing kidney disease and is currently the “gold standard” for diagnosing kidney disease. Kidney biopsy is a very important examination tool, which is of great significance in the specific clinical work for kidney disease, such as clear diagnosis, guiding treatment, judging prognosis, exploring pathogenesis, judging efficacy and its mechanism, etc. Its value cannot be replaced by other blood and urine tests and imaging examinations. Many renal diseases have different pathological manifestations but very similar clinical manifestations, such as both manifesting as proteinuria or hematuria, which makes it difficult to determine the diagnosis based on clinical laboratory tests and general examinations alone and is not conducive to treatment. Some studies have shown that the revision rate of clinical diagnosis after renal biopsy is 34-63% and the revision rate of treatment plan is 19-36%. It can be seen that kidney biopsy does provide great help to clinical diagnosis and treatment. In the last decade or so, kidney biopsy operation techniques have made extraordinary progress. This is partly due to the improvement of puncture needles and partly due to the application of ultrasound technology. With ultrasound guidance, physicians can get a clearer picture of the size and structure of the kidney, thus significantly improving the safety of the procedure and the success rate of the retrieval. Because of this, kidney biopsy has become a common examination method at home and abroad. At present, our department adopts B ultrasound-guided automatic biopsy gun kidney puncture biopsy, which is characterized by great safety, high success rate (more than 98%), less pain and fewer complications. Which patients should have a kidney biopsy? Theoretically, for most renal parenchymal diseases, renal puncture can be performed without contraindications. The recent foreign opinion is that proteinuria, microscopic hematuria, unexplained renal failure and systemic diseases with renal lesions are all indications for renal puncture. However, in practice, we believe that renal biopsy should be performed in the following cases: 1. unexplained hematuria and proteinuria. 2. Acute tubular and interstitial lesions. 3, nephrotic syndrome, chronic nephritis, IgA nephropathy, acute nephritis. 4.Acute renal failure of unknown cause. 5.To determine whether the transplanted kidney is rejection. 6.Systemic disorders and kidney, such as systemic lupus erythematosus, allergic purpura, nodular polyarteritis, etc.