Hematuria is the most common symptom of urological disorders in children. Hematuria can be divided into visual hematuria and microscopic hematuria. Hematuria is defined as higher than normal red blood cells in the urine. Definitive diagnosis depends on microscopic examination: clean fresh middle urine centrifuged urine sediment red blood cells ≥ 3 per high-powered microscopic field, or urine sediment red blood cell count > 8×106/L for more than 3 times to have pathological significance. If the urine contains more than 1 ml of blood per 1000 ml of urine, the urine can be observed with the naked eye to be washed water-like or tea-colored, which is called sarcoid hematuria. Urine occult blood test is only used for screening and cannot be used as a basis for diagnosis. It is not difficult for clinicians to determine the diagnosis of hematuria, but the cause of hematuria is complex and sometimes it is very difficult to determine the cause of diagnosis.