Hematuria, especially microscopic hematuria, is one of the common clinical manifestations. Determining the source of hematuria is of great significance to clarify the cause and treatment. Morphological observation of urinary red blood cells can be divided into two types: 1. Homogeneous type: urinary red blood cells are basically normal in shape and size, suggesting that hematuria is caused by non-glomerular diseases, mostly seen in renal tumors, renal tuberculosis, renal trauma and urinary stones, also known as non-glomerular source hematuria or surgical hematuria. 2. Polymorphic type: urine red blood cells have various morphological changes, either in the shape of bread loaf, or in the shape of gourd, with different sizes and broken red blood cells, suggesting that hematuria is caused by glomerular diseases, mostly seen in acute nephritis, chronic nephritis and secondary nephritis, also known as glomerulogenic hematuria or endoscopic hematuria (more than 70% heteromorphic). Phase contrast microscopy is applied to identify glomerulogenic and non-glomerulogenic hematuria with a high diagnostic compliance rate.