Proteinuria 3+ is not definitively a stage of kidney disease, and the stage of kidney disease is based on glomerular filtration rate. Chronic kidney disease is divided into 5 stages according to glomerular filtration rate, but stage 1 and stage 2 of chronic kidney disease generally require symptoms such as hematuria and proteinuria. Stage 1: normal or elevated GFR, GFR ≥90ml/(min-1.73m2), prevention and treatment goals and measures: diagnosis and treatment of the cause of kidney disease, alleviate symptoms; protect renal function and delay progression. Stage 2: GFR mildly reduced, 60 to 89ml/(min-1.73m2), prevention and treatment goals, measures: assessment, delay the progression of kidney disease; reduce the risk of cardiovascular disease. Stage 3a: mild to moderate reduction in GFR, 45 to 59 ml/(min-1.73m2), prevention and treatment goals, measures: delay the progression of kidney disease. Stage 3b: moderate to severe reduction of GFR,30～44ml/(min-1.73m2), prevention and treatment goals and measures: evaluation and treatment of complications. Stage 4: severe reduction of GFR,15～29ml/(min-1.73m2), prevention and treatment goals, measures: comprehensive treatment; preparation for renal replacement therapy. Stage 5: End-stage renal disease, <15ml/(min-1.73m2) or dialysis, prevention and treatment goals, measures: timely renal replacement therapy. Therefore, proteinuria 3+ alone can not determine the stage of kidney disease, when there is urine protein 3+, it is recommended that patients go to the hospital in a timely manner, under the guidance of the doctor to improve the examination, to clarify the cause of the disease, to be appropriate treatment, to slow down the rate of disease progression.