Objective To study the assessing value of high-resolution magnetic resonance imaging (HR-MRI) in the narrow degree of middle cerebral artery atherosclerosis. Methods A retrospective analysis was performed for 50 cases with middle cerebral artery atherosclerosis, which confirmed by surgery and pathology from January 2009 to February 2009. The patients were performed MRI and DSA examination, the value of HRMRI in the narrow degree of middle cerebral artery atherosclerosis was evaluated with the DSA results as the golden standard. Results 48, 8, 18, 15, 6 segments of no stenosis, mild stenosis, moderate stenosis, severe stenosis, vascular occlusion respectively were showed in both MR-MRI and DSA. The narrow degree of 95 segments in HR-MRI were exactly the same as DSA, the diagnostic coincidence rate was 95.00%. There were 5 cases of inaccurate assessment for higher or lower in HR-MRI, the percentage is 5.00%. Conclusion The coincidence rate of HR-MRI in the narrow degree of middle cerebral artery atherosclerosis was high compared to DSA, HR - MRI has certain diagnostic value in the diagnosis of intracranial vascular stenosis, which is worthy of clinical popularization and application.