Urine protein excretion rate between 20-200 mg per minute or 30-300 mg per 24 hours is called urinary microalbumin. When urinary microalbumin is present, urinary protein is usually negative in routine urine testing, so it is undetectable in routine urine testing. When urine microalbumin>150mg, urine routine test will appear positive for urinary protein, the appearance of urinary protein suggests that the glomerular filtration barrier is damaged, and a large amount of protein leaks out of the urine through the glomerulus. Long-term large amount of proteinuria will cause glomerulosclerosis, renal matrix hyperplasia, resulting in renal function damage, so the emergence of positive urine protein should be identified as soon as possible to identify the causes of early intervention and treatment, to prevent the disease from progressing, resulting in chronic renal failure occurs.