Objective The separation of various proteins in urine was used to differentiate the types of urinary protein to determine the site of diabetic kidney damage and lesions. Methods We used sodium dodeeyl sulfonate - agarosegel electrophoresis(SDS - AGE) to detect the unconccntrated urine on 108 cases patients with diabetic nephropathy urine specimens analysis. Results The results of urinary protein electrophoretic of 108 patients displayed: 4 eases for renal tubular proteinuria, 10 eases for physiological proteinuria, 22 eases for glomerular proteinuria, 72 cases for mixed proteinuria. Conclusion Urine protein electrophoresis for diabetic nephropathy patients with positive can distinguish the various components, and to understand the degree of kidney damage and lesions. This method is low -cost, non - invasive and highly sensitive. The film can be stored. It is worthy to be popularized.