Objective To investigate the imaging characteristics and diagnostic value of tri-phase dynamic enhancement scan with CT for acute renal infarction. Methods The image features of CT plain scan and tri-phase dynamic enhancement scan of 10 patients (19 sides) with acute renal infarction were retrospectively analyzed, and the CTA expression of 6 patients were observed. Results Fourteen acute renal infarction lesions of 10 cases were diagnosed. The CT scan showed there were 4 cases with enlargement of kidney, and the other 6 cases were of no abnormality. The tri-phase enhancement CT scan showed there were 6 cases of unilateral renal infarction and 4 cases of bilateral renal infarction, which totally involving 14 sides. The acute renal infarction lesions lacked of high density region in the corticomedullary in cortical phase, and there were wedge-shaped hypodense area, even low density of full kidney in parenchymal phase and pyelographic phase. The a-cute renal infarction lesions were revealed better in parenchymal phase and pyelographic phase than in cortical phase. Six cases of CTA re-vealed the responsible vessels of renal infarction lesions and the other vascular diseases. Conclusion CT tri-phase dynamic enhancement scan has important value in the diagnosis of acute renal infarction, and CTA can identify the responsible vessels of renal infarction lesions.