Diabetic nephropathy is kidney damage caused by diabetes itself, clinically marked by the presence of persistent proteinuria, i.e., persistent albuminuria >200 mcg/min or 300 mg/24 hours, usually accompanied by diabetic retinopathy. Diabetic nephropathy can occur in about 20% to 40% of patients with diabetes. the incidence of nephropathy in type 1 diabetic patients is related to the duration of diabetes, with an incidence of 40% to 50% in those with 20 to 25 years of disease, and about 20% to 50% in type 2 diabetic patients. The incidence of diabetic nephropathy in patients with type 2 diabetes is about 20% to 50%. Diabetic nephropathy is one of the most important causes of disability and death in diabetes. In developed countries in Europe and the United States, the proportion of diabetic patients in dialysis patients has long exceeded that of nephritis (more than 40% in the United States, ranking first). The situation in China is not optimistic either. Although the proportion of diabetic patients is lower than that of nephritis, the proportion continues to rise, mainly due to the increasing prevalence of diabetes in China, and the control efforts are far apart. The damage of diabetes to the kidney is mainly due to the damage of high blood sugar to the glomerulus and renal blood vessels. There are about 1 million glomeruli in human kidney, and each glomerulus is a tiny artery. Long-term hyperglycemia can gradually cause glomerulosclerosis. High blood sugar can also damage the renal arteries, long-term hyperglycemia can lead to renal artery sclerosis or even narrowing, followed by a decline in kidney function. Diabetic nephropathy is a chronic process. Its early clinical symptoms are often not obvious, and microalbumin (urinary albumin excretion rate of 20-200 μg/min, or 30-300 mg/24 hours) can often be seen; while in the clinical nephropathy stage, the urinary albumin excretion rate exceeds 200 μg/min, or 300 mg/24 hours, or the total urinary protein exceeds 0.5 g/24 hours. Approximately 10% of patients with diabetic nephropathy clinically present with nephrotic syndrome, with urinary protein excretion rate >3.5 g/24 hours and reduced serum protein, which may be accompanied by edema. The prevalence of chronic complications of diabetes mellitus is high and dangerous, and great attention must be paid to its prevention and treatment, the key lies in early prevention and treatment and comprehensive prevention and treatment. First of all, we should pay attention to early prevention and treatment. Patients with diabetes mellitus should have their urine routine and urinary albumin excretion rate checked regularly, especially those with a history of diabetes mellitus for more than 5 years, and should be tested at least 2 or more times a year. Controlling the patient’s blood sugar is a basic measure to prevent and delay various chronic complications of diabetes. Blood glucose must reach the standard, i.e. fasting blood glucose level <140mg/dl (7.8mmol/l), 2 hours after meal blood glucose level <180mg/dl (10.08mmol/l), glycosylated hemoglobin down to below 7.0%; if some patients have fasting blood glucose level <110mg/dl (6.1mmol/l), 2 hours after meal blood glucose level <140mg/ dl (7.8 mmol/l) and glycosylated hemoglobin drops to below 6.5%, it is more satisfactory. At the same time, comprehensive prevention and treatment should be emphasized. It mainly includes the following aspects: improvement of lifestyle, active control of hyperglycemia, hypertension, proteinuria, hyperlipidemia, hyperuric acid, high body mass index (obesity or overweight), and mitigation of microangiopathy. Urine microalbumin must be checked regularly for early detection of renal damage and early treatment. In combination with hypertension, blood pressure should be actively controlled to ensure that the lowering of blood pressure reaches the standard (below 130/80 mmHg). Healthy lifestyle mainly includes strict limitation of staple food intake, avoidance of sweets, proper exercise, weight control, and smoking cessation. At the same time, protein intake should also be appropriately restricted, generally 0.8 to 1.0 g/kg/day, and 0.8 g/kg/day or less after the appearance of proteinuria.