The urine test is very useful, through the urine test can make the most basic judgment. To see if there are white blood cells in the urine, if there are white blood cells, we should consider the possibility of urinary tract infection; if there are red blood cells that there is bleeding in the urinary system, bleeding may be trauma, tumors, or may be caused by stone friction. If there are red blood cells and white blood cells, and also proteinuria, pay attention to the possibility of renal tuberculosis. If simple proteinuria may be pyelonephritis, glomerulonephritis, tubular nephritis and so on. If there is positive urine bilirubin and urobilinogen, there may be disease in the hepatobiliary system. Urine ketone body, urine sugar can assess the control of diabetes mellitus; urine specific gravity can assess whether the amount of water to drink enough, whether there is a large number of metabolites in the urine; urine PH value can measure the kidney’s acid-excretion and alkalinity-retaining function is normal or not. So a urine test is one of the most basic tests that can make the diagnosis of many diseases.