Objective To establish a diabetic nephropathic rat model and to study it's kidney lesions. Methods 40 male Wistar rats were randomly divided into control and experimental diabetic groups, 20 per each group. Diabetic rats were induced by one intraperitoneal injection of streptozotocin (STZ) in a dose of 65 mg/kg. The rats were breed for 14 weeks. During the experiment, the blood glucose and urine glucose were measured and gross health status was observed. Finally, serum creatinine (SCr), blood urea nitrogen (BUN), urine protein and urine albumin were assayed, and renal pathological changes were examined by light and electron microscopy. Results The diabetic rats showed increased SCr, BUN, urine protein and urine albumin levels and hypertrophy of the kidneys. The renal pathology exhibited glomerular and tubulo-interstitial alterations. Conclusion The STZ-induced rat diabetic model have certain glomerulus and tubulo-interstitial lesions and can be used in diabetic nephropathy studies.