Objective To analyze the changes of renal histopathology and its significance after acute spinal cord injury in rats. Methods According to the random number table, 91 adult female SD rats were divided into sham group (Group A, n=21), simple spinal cord injury group (Group B, n=35) and bilateral adrenalectomy group (Group C, n=35). Allen's injury model of T10 spinal cord was produced in rats using a 10 g×25 mm weight drop. Laminas were removed in Group A, but leaving the spinal cord intact. Bilateral adrenalectomy was performed 5 days before the operation of spinal cord injury in Group C. Rats were sacrificed at 6, 12, 24, 72 hours, 1 week and 4 weeks after injury respectively. Pathological changes of renal tissue were observed by gross anatomy and optical microscope. Hematuria was observed at 6, 12, 24, 72 hours and 1 week, and microhematuria was tested. Results In Group B, renal hemorrhage, edema and inflammatory infiltration were observed at 6 hours, reached a peak at 12 hours and 24 hours, relieved at 1 week, and gradually returned to normal at 4 weeks. Pathological changes were not observed in Group A, and had a slight degree in Group C. Positive rate of gross hematuria in Group B was higher than that in other two groups (P 0.05). Conclusions Renal hemorrhage, edema and inflammatory infiltration appear in the early stage after acute spinal cord injury in rats, as may be the pathological base of hematuria, renal failure and urinary tract infection. Attenuated renal histopathology and hematuria after bilateral adrenalectomy indicate adrenal hormones and receptors may be involved in the pathogenesis of early renal injury after spinal cord injury. Key words: Spinal cord injuries; Kidney; Pathology; Hematuria