Tubular atrophic lesions, i.e., focal segmental glomerulosclerosis (FSGS), is a common primary glomerular disease in children and adults with nephrotic syndrome (NS). Its histopathologic feature is glomerular segmental scarring with or without intracapillary foam cell formation and adhesions in the glomerular capillaries. Focal means that only part of the glomerulus is involved (50% of the glomeruli involved); segmental means that part of the lobules of the glomerulus are involved; and glomerulosclerosis is a staged glassy change or scar formation throughout the glomerulus. Pathologic features are mostly accompanied by tubular atrophic lesions and renal interstitial fibrosis. Tubular atrophic lesions occur more often in children and adolescents, and are slightly more common in males than females. A few patients have upper respiratory tract infections or allergic reactions before the onset of the disease. The most common first clinical symptom is nephrotic syndrome, about 2/3 of the patients have a large amount of proteinuria and severe edema, the amount of urinary protein can be 1-30g/d, about 50% of the patients have hematuria, microscopic hematuria is common, and occasionally see the naked eye hematuria. Adults in 30% to 50% of patients with mild persistent hypertension or manifested as chronic nephritis syndrome, patients with 24h urine protein 3.5g / d, edema is not obvious, often hematuria, hypertension and renal insufficiency, while more than 50% can be the manifestation of nephrocystic syndromes, there are obvious three high and one low clinical manifestations. A few patients have no obvious symptoms, and proteinuria is occasionally found in routine urinalysis. This type of asymptomatic proteinuria can last for a long time and has a good prognosis. A small number of patients with this type of proteinuria may progress to end-stage renal failure. Proteinuria is mostly nonselective, but can be highly or moderately selective in the early stages. Serum C3 concentration is normal and IgG levels are decreased. There are often manifestations of impaired proximal renal tubular function. Upper respiratory tract infections or allergies can exacerbate these symptoms. There is no reliable clinical indicator for the diagnosis of tubular atrophic lesions, and in the diagnosis of FSGS, renal biopsy should be relied upon and care should be taken to exclude various possible secondary factors, such as HIV infection and drug addiction. Careful history, physical examination and laboratory tests can help in the differential diagnosis. For example, FSGS should be suspected in patients presenting with nephrotic syndrome or simple proteinuria with proximal tubular impairment; persistent nephrotic syndrome with hypertension, microscopic hematuria, and nonselective proteinuria; and hormone insensitivity.Renal biopsy is helpful in the diagnosis of a typical focal segmental glomerulosclerosis (FSGS) characterized by focal damage affecting a small number of glomeruli (foci) and a localized glomeruli (segmental). Involvement of the glomeruli begins in the proximal medulla and involves only a few capillary loops in mild cases, while in severe cases, most of the glomeruli are affected. The lesions appear as a homogeneous, cell-free or minimally cellular hyaline degenerative material (intra-loop foamy cells, hyaline droplets), and in severe cases, there are adherence to the glomeruli, epithelial proliferation of the visceral epithelial cells to form a cap-like structure, or even an umbilical lesion.