Nephrotic syndrome is a clinical syndrome caused by increased permeability of the glomerular filtration membrane, resulting in the loss of large amounts of plasma albumin from the urine. It has four major features: massive proteinuria (qualitative >+++, 24hr quantitative >50mg/kg); hypoproteinemia (plasma albumin <30g/L); hypercholesterolemia (blood cholesterol >5.72mmol/L); and varying degrees of edema. Various primary, secondary, congenital or hereditary glomerular diseases can cause this disease, but the vast majority (more than 90%) are primary in pediatrics. 1, clinical typing (1) simple type Only those with the above four characteristics. (2) Nephrotic type In addition to the above, one or more of the following four features are present: hematuria: red blood cells >10/HPF on 3 centrifugal urine tests within 2 weeks; recurrent or persistent hypertension, 17.3/12.0kPa in school-age children and >16.0/10.7kPa in preschool children, excluding corticosteroids; persistent azotemia, urea nitrogen >10.7 mmol/L, and exclude blood volume deficiency; repeated reduction of total complement or C3. The common pathological types are microscopic lesions (MCD) and non-microscopic lesions, the latter including focal segmental glomerulosclerosis (FSGS), membranoproliferative nephritis (MsPGN), membranous nephropathy (MGN) and membranoproliferative nephritis (MPGN). In children, MCD is common, followed by FSGS and mild to moderate MsPGN. MGN is rare in pediatrics in primary cases, accounting for only 1 to 2% of cases, and the vast majority are secondary, especially hepatitis B virus-associated nephritis. MPGN is a more serious type of pathology and requires early and timely diagnosis and treatment.